@ThiloteE Yes, indeed, this has nothing to do with the rtl88121bu driver (should have been clearer in my message): @bjlockie mentioned running that particular usb key/chipset, and described having the very problem I am experiencing, so I was hoping to maybe get some tips from them if they ever managed to fix it.
Supposedly this is a kernel-supported driver and plug-and-play (had to do a bit of tinkering, but quite possibly due to running OSMC on a RPi4, rather than a more straightforward flavour of Debian/Ubuntu), but it seems odd that such a major issue would still be occurring on this chipset (which consistently comes up on top on lists of best-supported). My knowledge of driver tinkering is unfortunately quite low, so I am barely able to figure out whether I am indeed running a recent, or the most recent, version
@bjlockie Thanks for taking the time. And yes, this indeed seems to be a bug in the RPi4 USB firmware
My googling also took me in the direction of disabling SG, but much like the people in that GitHub thread, this did not seem to remove the problem altogether (hard to tell if it's helped, since the bug is quite unpredictable)…
morrownr told me the in-kernel driver for rtl8812bu is decent and speeds and stability roughly comparable to the out of kernel driver starting from kernel 6.2 or better the 6.3. The next release of OpenWrt 23.05 will use the 5.15 kernel. The release after (next year) will be likely 6.1. So unless the rtw88 driver is not backported, it will take two years until this hits OpenWrt.
If you only need the driver for your client device and not as accesspoint, you could install a rolling release linux distribution operating system (for example Fedora), which are those that usually follow the newest kernel versions more closely. If you cannot or are unwilling to do this, you can try the non-conforming out of kernel drivers, which are based on the official open sourced version from Realtek and usually are maintained by random, but helpful volunteers on the net (e.g. by morrownr here), but they bring their own share of problems and maybe some features will not work either.
There is also the package kmod-rtw88 in OpenWrt. You could try that one too! Who knows, maybe the performance is actually good enough for your usecase. Edit: see how to here
Edit²: the kmod-rtw88 package does not support USB until kernel 6.2 or something so yeah...
I was working with Archer T4U v3 rtl8812bu driver back then in 2020-2021 it works perfectly I like because it can scan 5G networks too somewhere those years the Kali Linux updates made it unavailable etc. I talked with the developers they say they want it paid.
