Konqueror mount error

Hello all, Debian Buster with R.14.07 (Development). I have an external SATA to USB enclosure with removable discs. When I slip a disc in and turn it on, I get a Konqueror error (unable to mount this device, see attachment). However, I can mount it with no problem from the command line. My guess is that it's a timing problem, Konqueror trying to mount something that is not yet available, but I don't know what to do. I did not have this with Stretch and "stable" TDE, so it might also ave to do with de "Development" version. Thierry