[PD] Recognizing USB MIDI interfaces on Pd 0.48.1 (Debian 9.5)

[Ingo]

Hi everybody,

I know this has been coverd before but somehow I can't find it.

I'm having a problem that after switching to Pd 0.48.1 on Debian 9.5 I
cannot recognize USB MIDI interfaces anymore without restarting Pd.
Can anybody tell me how to do this or point me to the relevant information?

I used to simply recall the MIDI dialog and it was there - that's not the
case anymore.

Thanks a lot!
Ingo