MIDI keyboard connection gets lost

since the last update, sometimes Dorico loses the connection to my MIDI keyboard. Until now I could unconnect and reconnect the USB cable to the keyboard - or even just use the on/off switch, and Dorico would receive the MIDI signals (keypresses) again.
Now this does not work any more. It seems I have to quit Dorico and relaunch it, so I can use the MIDI keyboard again. Is there a more elegant way, of which I don’t know?
I am on a Mac btw.

What keyboard are you using?

The keyboard is a very standard M-Audio eKeys49.

There haven’t been any changes to Dorico’s handling of MIDI devices on macOS that would account for a change in a recent version, Klaus. It might be worth trying a different USB port on your computer or hub if possible. I know that most (all?) M-Audio keyboards are bus powered, but it would also be worth checking for any fluctuations in power delivered to the keyboard as well.

Daniel, I watched this for a couple of more days, where I had to relaunch Dorico a few times. The last 4 days though I left a big project open, just saved from time to time and every morning the MID keyboard was working no problem.
Then I opened another small project, choose to activate sound, and closed it again. After this, the MIDI connection to Dorico was lost. Before relaunching Dorico, I changed to Play mode, re-applied Playback Template and loaded sounds for unassigned instruments. After that, MIDI was back on.
I will try this method the next time again.

If you deactivate a project for playback then, for the moment at least, you also disable MIDI input, as that’s provided by the audio engine and it’s only available when the project is activated. I guess this probably explains what you’re seeing?

Does this mean, if I have more than one “sound activated” projects open, that solely the foreground project actually is active and only when switching back to another one, that one gets re-activated?
What I found interesting is, that also the midi connection got lost, but could be re-enabled.
It would be good to know, how one exactly can trigger the midi connection, while the application is open.
Sorry, if this all sounds confusing…

If all of the projects you have open are activated for playback, then Dorico will unload and reload the required sounds when you switch between them. Provided the project is activated for playback, the MIDI keyboard will work. If the project is not activated, then it won’t.

Daniel this sounds very basic, clear and simple (as it should be). This also implies that Midi-connection will be triggered again, when I take a background project to the front.
You might notice, that I still have functionality from another Software in mind, where one could look for midi devices in the Preferences>Input Devices>Find New Input Devices…