Hmm, that’s not normal - though bluetooth is only good for about 10m line of sight.
RF interference can also decrease the effective range - anything in the 2.4GHz region can have an impact: Microwaves, WiFi, and USB 3 devices have all been known to cause issues with bluetooth, as well as the shielding from anything metal being in the way, such as a metal Pi Case.
What BT device are you using? And what else do you have near it?
