After deconstruction of some belts there are random power warnings left, overpainting with new belts and removing them doesn't help.

https://youtu.be/tVI9VIaxgg0

there was a miner setup like the top row.
used bot deconstruction with blacklisted power poles, so there be power all the time.
after deconstruction finished successfully, I removed the power poles to find those ghost power sources where the belts were.
happened only on some spots as it was full length belts.

tried to place new belts (manually and bots, while powered and while unpowered) and remove them (manual/bots) but could not reproduce it.
when I build an unconnected power pole, there are items with belt icons listed from "Powered Belts"
titled "Unknonwn key: entity-name.transport-belt-power" so it is those.

could there be a way to check all power consumers on map and if there is no belt on top remove them, like once at save start?

as I cant reproduce it I suspect this may well be because I added the mod midgame (very early but still), and this was one of the first mines so those belts might have been there before. there were no other issues like that in everything else I've built and removed so far
will report again when I have some more info..

if anyone has the same problem, a workaround to remove those around the player is to use the command:

/c for _, entity in ipairs(game.player.surface.find_entities_filtered{ area={{game.player.position.x-1, game.player.position.y-1}, {game.player.position.x+1, game.player.position.y+1}}, type="electric-energy-interface"}) do entity.destroy() end