They did, thanks, but only to confirm what packages you have and your settings. The details of BT communications is a whole other level and a bit outside my paygrade.
If you have a BT USB dongle you could try that, but I can’t recall how to disable the internal BT device. @sam_nazarko will know.
The other thing you could try is can you connect to any other BT device? Do you have another KB or mouse? Or you could even try your audio device. [How-to] set up Bluetooth audio