Unwanted Reverb is always applied on playback

I'm using Musesounds, here in the screenshot electric bass.

• On entering the notes in note input mode, or when clicking on a note, there is no reverb at all. Good.
• On playback via the playback button, it adds unwanted reverb.

Since, as described, it can play Musesounds free from reverb I conclude, Musescore adds an effect at some point. Some forgotten call in code maybe.

I am wondering why nobody reports? Can anyone confirm?
Mixer attached.

Thx