This is a strange little bug.i am struggling to see how it could possibly relate to changing a track. There is a bug in the Sidebar Player not showing the repeat one symbol, so even though MB is on repeat one the sidebar player shows repeat all. I will fix that. Other than that i can only think that the skin you are using at high DPI is rendering the repeat button at the same location as the next track button?
I installed the latest 3.0.5929 on a clean 2.5 portable installation, on a W10 tablet with 125% display setting.
When I for example set 'repeat 1' while a track is playing, , and then select another track to play, the repeat setting switches to 'repeat all'.
When I then set it e.g. to 'repeat none', and skip to another track, the setting switches to 'repeat 1'. Etc.
So somehow after having changed the repeat setting, when as a next step you skip a track, that simultaneously toggles the repeat switch.
The repeat and next buttons are far apart, but it might be some skin issue indeed.
I noticed that after the player controls were pressed, they kept displaying the highlight image, even after released.
They will change back to normal state when you press at some other panel.
Something similar with the progressbar, when I click a position there, the time of that position pops-up, and doesn't go away either.
So while it looked as if the repeat state was changing by itself after the playing track ended, it doesn't.
I now understand that after having pressed it, it shows the highlight image, and keeps showing that, until another track starts playing.
You will notice that especially with skins such as Jistme the Nightbee, since the highlight images for repeat and shuffle buttons are images for the'next state'.
So it is some image refresh issue.
Perhaps there is some error in that skin that makes this happen?
One rule that I deliberately have broken, is that play and stop buttons overlap. Perhaps that is a factor?
I connected a mouse to the tablet, and with that the issue doesn't arise.
So it is related to the touch-screen interface.