I'm getting same issue with one app on my Roku Stick + (Broadway HD). Lip sync is fine to start with but within a few minutes it starts to go out until its unwatchable. It only affects this app. I've tried everything - re-installing the app and other methods described above but nothing works . This only started happening after the latest Roku software update on my stick +. I've informed Broadway HD who are looking into it but since it started after latest Roku update I'm thinking it's a Roku issue . Really annoying as I pay a subscription to Broadway HD and in the UK using Roku is the only way to watch it on my Sony Bravia TV.
I saw the post above and updated my firmware hoping for a solution. I have an older Roku Express from 2017 and this update made no difference. As a test I left my Roku running overnight and by morning I was a full minute out of sync. As always if I restart the app I am back in sync for a while but get progressively out of sync the longer I stay connected. This is one of several posts I have made on this or related out of sync topics since I first noticed this issue in the fall of 2019 and I am still hoping Roku will fix this issue on all of their players. If not they should offer an upgrade to a model that does not constantly go out of sync.
This is my second post in a few days. I am happy this worked for you but for me its definitely worse since the latest software update. The audio goes out of sync within a couple of minutes and just gets worse as time goes by. I feel I have tried every suggestion on this discussion and nothing has worked. I have wasted enough time on this and Roku obviously don't care so maybe its time to try Fire TV.
I have the Roku 3700X Sync issues with Pluto TV, Spectrum App, & Some other TV apps. Netflix however is fine & Sling seems to be ok last time I used it. Is Roku going to fix this issue or time to trash & make bad reviews on this product on Social Media & YouTube.