Why airpods pro disconnect immediate from iPhone when I am near to my mac book while playing content

When I hear content on my iPhone connected to my earpods and comming in the range of my mac book, immediately the earpods disconnect from my iPhone. When I try to reconnect to the iPhone it fails. In the display of my iPhone the earpod connect icon is visible and also in the bluetooth menue the airpods marked as connected. When I try to do a call with airpods the option immediate jumps back to phone speakers and when I try to hear music it's the same. I try to reset and also used a second pair of airpods with the same result. This happens since the last update of my mac book (running BigSur V 11.6) MacBook Pro (Retina, 15', Mid 2015).

Cheers