Roku Remote Stops working with Stream Stick +/4K over time (2hrs)

I have two Roku Steaming Stick, one + (3810X) and one 4k. Both are exhibiting the same problem.

When I turn the TV/Roku on, everything all works perfectly.

But after watching for a movie or a few TV shows, the remote ceases to work. I purchased the second Roku as I thought it might be a faulty remote, but the same behavior persisted.

The Streaming Stick is playing shows perfectly, so I dont think its a wireless network issue, and when I use the Roku remote app on my phone everything works perfectly.

To resolve the issue, I've been resorting to powering the TV and Roku down and then back up. But this is very frustrating.

My Roku Streaming Stick+ is running version 11.5.0 build 4312-50

The remotes are the Roku Voice Remote that came with the Streaming Stick+/4K

Appreciate any assistance in getting my remotes working reliably.