I'm experiencing weird behaviour with my wireless Dell keyboard. After pairing it seems to be stuck in a connection loop. It's added again and again until I turn it off. What's more, other bluetooth devices are blocked as well. Here is a GIF to illustrate the issue:
Luckily, the keyboard and mouse come with a USB dongle, which works fine. Only on direct bluetooth connections (channel #2 and #3) there is this problem. The mouse, on the other hand, works perfectly fine on the dongle channel as well as on the two bluetooth channels. And so does my Microsoft Surface keyboard, no problems there.
I used the Dell keyboard on a daily basis with Pop!_OS on this same laptop. It also works fine with my Mac and all my other devices. It's just behaving badly on elementaryOS.
A solution would be to buy another surface keyboard, but clearly it's a software issue so maybe there is an easy fix?