Bluetooth Volume only two Levels on Android 7.1.1

[AgentBukky]

After Updating my Xperia X to 7.1.1, the bluetooth Volume can only be adjusted between two Levels on the whole slider!  It jumps after the first approx.

 20% from left scale of the slider to a higher level.No further change of Volume on the remaining 80% of the slider. With 7.0.0 everthing was fine like on my Xperia Z2 tablet. 

[AgentBukky]

After a little more testing,  i figured out that this only happens when it is connected by aptX, normal streaming to a JBL Go allows fine Volume settings 😞