error using tty.usbserial-xxxx: could not open, resource busy

Since one year I'm using a MacBook Pro 13 upgraded to Catalina in October. I use the Mac to program same embedded module via RS232 (different adapters with different chips, e.g. FTDI) and it is still working. Last Monday I changed to a new MacBookPro 16. I used a backup and all worked proper, but I can't connect to any USB-to-Serial adapters. I got the same >error could not open port /dev/tty.usbserial-xxxx: Resource busy ... I tried to reinstall all corresponding drivers, but without success.