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.
Actually I haven't been able to get Bluetooth 5 dongles to work on Linux. I only have success with Bluetooth 4 dongles.
What are you going to use the Bluetooth dongle for? Connecting Bluetooth peripherals, or headphones? If it's exclusively for Bluetooth headphones, using a Bluetooth audio dongle (which is detected as a USB audio device in Linux) works much better than using the Bluetooth 4.0 usb dongle for audio purpose because you can use low latency aptx codex and Bluetooth 5 without messing with random drivers from some github repos
I'm pretty sure you can use aptx codecs using a Bluetooth 4.0 dongle and pipewire/bluez5. Just be aware when using them for gaming, if the game is cpu-bound and starved the system out of CPU time, the bluetooth audio might start to stutter. A Bluetooth audio dongle never stutter because they have their own independent Bluetooth stack, but they're about 10x more expensive than a Bluetooth 4.0 dongle (~$50) and can only be used for audio only.