@DLB26 I have a USB stick plugged into my Ultra at all times, and I've never had to do that. It's always been recognized. Are you powering your Ultra off when not in use? Not that I would expect that to make any difference, just trying to determine your use environment.
First, I should mention that I have an older Ultra purchased in 2019 (model 4660X2) but kept updated. Yes, it gets powered off after each use.
OK, I don't have that specific version, I have the 4640, 4670 and 4800 Ultra. But most likely it's the fact you're powering the Roku off when not in use, and the USB port isn't powered up in the correct sequence to allow the OS to recognize there's a drive connected. If that's the case (and it is the most likely reason) then there's nothing you can do as a user to change it, other than leaving your Roku powered on at all times. Your Roku uses very little power, so it's not really necessary to power it off when not in use. In fact, some argue it's actually harder on electronic devices to power them off and on continually. Myself, all my streaming players are powered at all times.
Ok, I'll give that a shot. One other thing for anyone that is listening, the RMP obviously is not something Roku has spent much time developing. It is not very sophisticated. The media player in my LG OLED TV is much better with a more advanced UI and more features. Also it seems no one else has wanted to develop a media player app for Roku. As popular as Roku is, it would be good for them to spend some time working on the player.
RMP hasn't had any updates for video playback for more than three years. There's been a couple of fixes for music playback, but the UI hasn't been touched since it was changed from the original version something like 5+ years ago. They really need to put some effort into it, or give up and let someone else come up with a good media player. There's already one or two in the channel store that work better for USB playback, but there's nothing for people that use DLNA servers for their media streaming.
I am having exactly this same issue, after a Roku software update some weeks ago. The device now periodically asks, out of nowhere, if other streaming services can have access to my drive. I say no. The Roku box then immediately stops recognizing the drive. The problem can only be solved by unplugging and replugging the USB drive, at which point Roku recognizes it for an hour or two before the whole nonsense starts again.
This is extremely annoying, and clearly other people are having the same problem. The fact that Roku has not isolated this problem within a few days and solved it with an immediate firmware update reflects very badly on the company.
I got it!
My situation: I had a USB stick for media. I took it out to add more media to it. I put it back. When I opened the app, I got the no-recognize error.
In my case, it was somehow a permission issue. The device forgot it was allowed to access the stick.
Solution: Take the USB stick out. Go to the Roku Media Player app. Put the USB stick in. That'll bring up the ALLOW? prompt. Allow it to access the stick. Once it is allowed to access it, it recognizes it.
Hope this works for you!