This sounds like the known issue. You might want to follow some of the issues that are open around this topic:
About half way down on the following page it says:
BlueALSA also allows to capture audio from the connected Bluetooth
device. To do so, one has to use the capture PCM device, e.g.:
$ arecord -D bluealsa capture.wav
Using this feature, it is possible to create Bluetooth-powered
speaker. It is required to forward audio ...