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?
Not saying this is the answer to your question, but generally, it’s the hardware/software unaccounted-for states that can’t easily be recovered from. So, rebooting would hopefully get it in a known “clean” state, and hopefully, not falling into that unaccounted-for state again.
Shitty, but works with some other things too. Angry, frustrated, hopeless? Sleep it off, maybe (not guaranteed) it will be better tomorrow.