It’s been the case for almost a year unfortunately. For some it started in 3.4: [3.4.0 onwards] Bluetooth turning on doesn't work
For others like me it came with 4.0: [release notes] Koli 4.0.1 - #183 by laustela
Jolla made me use wired headsets again 
Can you rather post on the original topic to up it again?