MacBook connects to the JBL Flip 4 and then disconnects

In the past, I was able to connect my MacBook to the JBL (but maybe it was another JBL, I am not sure), but now I am not able to, because it disconnects 5 seconds (or so) after the Bluetooth connection has been established. I already tried the procedure suggested in this answer , but nothing changed. Of course, I also tried to turn on and then off the Bluetooth, remove the device and search for it again, but nothing really worked (i.e. it finds the device again and connects, but then automatically disconnects it). So, any ideas? I am on a Mac OS Catalina (10.15.7). Btw, I am able to connect my Samsung Galaxy to the JBL. Also, previously, I was able to use the JBL speakers with a cable, but that cable broke (apparently), so I can't use it anymore, so I guess the problem is related to the Bluetooth.