Flex Duo Pixelating Badley and Voice/Video Not In Sync

[Tenngeezer]

Hi, I'm new to this forum.
I've had a Flex Duo for awhile now and up to the other day had zero issues. However My Sony Smart TV bit the dust and I replaced it with a Vizio Smart TV. I use Roku Express devices to stream all my content on all my TV's. I'm just not a fan of having to relearn how to navigate through operation of a device every time I change something, so the simple Roku device presents me a consistent interface for all of the family across all TV's. What my issue is, is when I reconnected the system having replaced the TV(Vizio) everything worked fine. ROKU put out over it's HDMI as it had before and all content was clear and in sync - the Flex Duo Homerun did not behave well - bummer.
What confuses me is why when nothing on it's input path was even touched/disconnected and the WIFI network it was connected to was exactly the same. The ONLY thing changed was the TV which is the sole terminus for the ROKU HDMI output. When the ROKU HD app was selected it displayed a very jittery pixelated image where motion seemed in slow motion and audio was out of synch with video - same across all channels from the antenna.
I checked all the connections and reset all devices and still the same output from Flex Duo - not good. I next hooked the antenna solely and directly to the Vizo TV and scanned all channels - got the exact same channel line up as before this problem. Picture quality was great no pixelation and everything was in synch. I like the ability to WIFI the antenna around our vacation cottage's 3 Tv's.

I reconnected the antenna to the Flex Duo and the problem is still there. I deleted the ROKU HD app and reinstalled it - nothing doing. I am clueless as to why this is occurring. I don't have any idea of failure modes or indications for the Flex Duo - so my Flex Duo may have failed? Prior to retirement I worked with electronics and computers and am comfortable trouble shooting things. I don't want to buy another Homerun replacement yet without being pretty sure it needs to be replaced.

It's a simple hardware config
Spectrum Internet Modem feeds Linksys Ac 1200 wireless router which is WIFI connected to ROKU Express and the Homerun Flex Duo connected to antenna
Vizio Smart TV connected via HDMI cable to ROKU Express HDMI Output.

Here are the details:
Flex Duo Model HDFX-2US
Device ID 10901337
MAC 00:18:DD:09:01:33

I couldn't retrieve the software build in the Flex Duo as I once was able to do - looks like updates have changed several things
ROKU Express HD app Ver88.0 build 20240220.

Thanks for your attention and hope some light can be shed on this issue

Regards Joe

[jasonl]

If you watch the same channel side by side on a phone, tablet, or computer, how does that look?

[Tenngeezer]

Thanks for your reply. I don't have the HD app installed on anything else - except on two other TVs also at that location. I can try to do a comparison later today when I'm at that location. I'll see if i can set up my laptop or Android phone with HD app. Thanks again.

Joe

[Tenngeezer]

I loaded the HD Homerun app on my android phone it connected perfectly. I also brought another dumb Hitachi TV with a Roko Express streaming interface and it too works fine. So it is looking like the Flex Duo is Ok - I did try both channels simultaneously, one on the phone the other on the Hitachi TV. Both ran fine. Went back to solo Vizio via Roku app - nogo, still looks like slow motion, lots of pixelation, and no audio?? There is no native app that can be installed on the Vizio TV. I am stumped why the Roku HD app via a regular HDMI input is doing this? Any suggestions?

Regards Joe

[jasonl]

Do you have the Roku located close to the TV? Some TVs emit a lot of RF that can kill wireless network performance for devices that are in close proximity, and if the TV itself is between the Roku and the router, the metal shield in the TV that is there to limit the RF emissions will also block the wireless signal. Moving it away from the TV and giving it a clearer shot at the router can easily double or triple wireless performance.

[signcarver]

What exact model of express as many only support 2.4GHz wifi (some are supposed to but only with certsin channels so some routers need to be manually configured to use only certain 5ghz channels or have features disabled as it gives the appearance of ) which often results in poor performance of mpeg2 ts streams particularly when live.

[imagexpo]

I'd also add I have a new Vizio and it uses more wifi bandwidth than anything else in the house. Vizio has added some free tv services that combine ota and internet. It was unusable for me - lag and buffering constantly.
The wifi bandwidth was so much I disconnected the tv from my network. It is now a dumb tv with the Roku only connected to wired ethernet and HDHR Everything works fine. You could try that as well.

[Tenngeezer]

Thankyou all for the help, advice, and suggestions! I apologize I've not been timely in responding, been pretty busy with family things.

First off I have got something working with the new Vizio Smart TV, I'll discuss this later in this post. I am not really liking the Vizio - I really wanted just a dumb 43"TV with an HDMI input and antenna input. Couldn't find one after some searching except for a Samsung commercial unit that was pretty pricey.

I did try segregating the router/WIFI and other items to lessen any "noise/crosstalk as was suggested. I also repeated the same set up on both WIFI bands 2.4 and 5 and no change. Another suggestion was to not connect the Vizio to network or internet ( which disabled voice command in the Vizio - I don't like voice control so I'm good with that) So essentially the Vizio is now a dumb TV.

I loaded the HD app on my Android phone and it works fine but the Roku HD app driving the Vizio is still a mess - so looks like the Roku is suspect and the Flex Duo is not suspect.

I have several Roku Expresses covering a few years so I brought over a two year old unit. The Vizio now works fine, smooth video, no pixelation, voice is good and in synch - yay. So evidently it is some Roku issue. I did also find that after a few minutes of the Vizio working the Roku would kick out and go back to it's Home screen. On the Vizio I set the HDMI input to "Standard" AND turned off CEC and that seems to have it fixed. Any where I placed the newest Roku Express the HD app produced a messed up video.

The problem Roku Express is a newer model and only a few months old:
Model 3960 Ver. 12.5.5 build 4174-ED

The working Roku Express is a older model
Model 3930 Ver. 12.5.5 build 4174-AE

The Roku's do update their software automatically - and has cause problems on occasion.
So I'll see if Roku can shed any light why the 3960 model doesn't work

Again thanks for the help and if I get any info on what the Roku issue is I'll update this forum

Regards Joe

[luric9957]

I had te same issue with a tivo, it seem related to the vizio hdmi input.
Google search for vizio out of sync audio, there is a lot of people with the same issue, the common point is the hdmi port.
I tried many thing, they work for a while and the problem will be back again. Remove all sound processing from the tv menu,
il will help.

[Tenngeezer]

Thanks for reply. I will try it when I am home. Have to say not a fan of Vizio TV.