Often with a Linux kernel update, or even after a first install of Linux in place of Windows, Bluetooth stops working and the advice is usually to just power off your computer, wait a bit, and then turn it on again. Bluetooth then miraculously works again.
I mean the issue could also come from other things (not starting the right kernel module etc…), but very often it’s just this simple trick that makes it work again.
So what is changing in the Bluetooth device when you do this power off/wait a bit/power on trick?
Can’t confirm, but I would assume that there is a capacitor in a few bluetooth modules that keeps some of the components charged, and that they only try to comminicate with the kernel after a power cycle.