As I pointed out in this thread, I had trouble removing the atheros firmware since bluetooth worked even after I purged the driver.
Today I booted into pureOS the bluetooth adapter was not recognized anymore. This is strange since I expected that to happen right after removing the driver and not five reboots later. But another strange thing is, that all addons vanished from the PureBrowser. uBlock-Origin and HTTPS-Everywhere are just not installed anymore.
I wonder about the reasons for this spooky behavior.