Can you recommend a Bluetooth dongle that support s version 5.3, not too terribly expensive and available in Europe? Preferably works out of the box on Ubuntu LTS, but compiling my own kernel is also acceptable.
For context my last attempt ended with one that only works with Windows 10, when no other Bluetooth receiver is connected. Cherry on top it needs troubleshooting wizard after each reboot.
If your system has a free PCIe slot you should be able to find a wifi card that will work. I personally am using an intel wifi board for bluetooth and have not had any problems with bluetooth. Their driver seems to be really stable on linux and in kernel and should be stable on windows as well. I got my m.2 card for about $20(usd) and wouldn’t expect that big of a difference for a standard PCIe card.
Good luck in whatever you end up doing.