There are several bug threads about this, most a few years old and they all say they’ve been fixed at the end, but I just noticed that this is happening for me.
I don’t know if this is happening again as I just did a reinstall of Linux Mint Cinnamon (X11) or if I just went a while without accidentally hitting the middle mouse in Obsidian.
All other programs seem to respect the option to disable this, though I also had to disable it in Firefox. In Obsidian it’s causing some minor problems when I hit the middle mouse button accidentally and only later notice text was pasted where it doesn’t belong.
Since in the bug threads there were some people who wanted and used this, I don’t think it’s a bug, I would just love a way to disable it.
I installed Obsidian via the .deb file.
Thanks 