No copy and past button's under ArchManjaro and Mate Ubuntu

[musikbear]

When selecting one note, with click on it and then ctrl+c and paste it - it place the note over the existing one, and not under the mouse cursor.

No it places the note at the play-head position

When selecting more notes with the select tool and then ctrl+c and past it - it placed randomly mostly partly over existing other notes

Same answer: First notes left edge at the current playhead position

[Crojav]

Excellent, did not know about that. Thank you, this helps me a lot to go on with Lmms.