Hello! I just recently bough my Flash Plus 2, 2 days ago. (And I don't wanna returned as it has been already fully customized in settings, apps, updates, accounts, etc)
I got this problem with pairing my Home Theater System with my FP2. It can connect but every time I play music, the audio stops every 5-8 seconds at playtime and then resume every 1 second. The music tends to become faster than it normally should. I tried disconnecting wifi while playing music and it's still the same.
I haven't removed the original plastic on the screen yet as I find it hard to look for the regular screen protector, I can only find tempered glasses and I don't prefer such.
Other than this everything about Bluetooth seems to work fine (e.g. file sharing)
I never had the same problem with my windows 10 mobile and my htc android phone.