1

Even after I change my phone firmware from Ireland to France and from France to Egypt, bBouldbeast still not work.

At all of the times I got this notifications :
"Android allows only one recorder working, so at first time you MUST remove or force stop ALL other recorders in your phone, otherwise this app will surely fail to record calls because of this. "

I swear I don't have any other recorder call on my phone

2

Please open "Settings > Apps & notifications > App permissions > Microphone", revoke the Microphone permission from all other apps. Then try again.