I'm sorry you're having this experience. At the top of the forum page, there is a search box (that's not meant to sound snarky). Pull down to search "this board" and search for "delay" or "sync." Sort by date. There's a lot of this in a lot of different contexts, and Roku has been completely unengaged on the topic. Every time someone posts about this, it's like "oh, this is the first time we've heard of this. Can you please provide..." There's no formal bug tracking. No followup with what to expect. People are just left to die on the vine.
"People are often amazed at how much we’ve done with the number of engineers we’ve got." (Roku CEO Anthony Wood, Austin Statesman, Oct 4, 2019). "Amazed" is one way of putting it.