These are (unsurprisingly) bugs in the realtek wireless drivers and need to be fixed there, chances that OpenWrt will be changed to workaround driver bugs (especially for drivers that aren't even used in any supported devices) are minimal.
Since OpenWRT is based on the Linux kernel, all you will need to do is to wait until kernel 6.2 (or something) has reached OpenWRT (or to help porting the 6.2 kernel to OpenWRT). From what I can hear, these in-kernel drivers may still need a little refinement though. They are also mainly pushed forward by volunteers. Any help is welcome, as (to my knowledge) Realtek has refrained from doing so. Unfortunately, Realtek is not one of these companies that at present time upstream their wifi drivers to the linux kernel. I own a 88x2bu, but next time I buy a device, I will take care to choose one that is supported in-kernel.
For now, your best bet would be to install an out of kernel driver. You will not be able to use OpenWRT with them, but these out of kernel drivers may be enough, if your use case is that of a simple wifi client. Sometimes they even support accesspoint (AP) mode or monitor mode.
Out of kernel drivers that are installed via dkms (these drivers need to be upgraded/removed before any attempt to upgrade to a newer kernel):
Unfortunately, at least with rtl8821cu, rtw88 does not work properly for 2.4 GHz. It either selects incorrect antenna or does not enable power amplifier properly, at least for me. I already contacted the authors.