Underspire map not updating after battle, after buying lanterns

Original title: Underspire map not updating after Dragon battle, unlock of gate

Specs
Steam - Windows 10 Home

Description
The underspire minimap does not update if you buy lanterns at 0 and then do a battle, even if you do not use a lantern. This can cause you to be stuck behind a locked gate.
Old desc: Sometimes the underspire minimap does not update after a dragon battle, and you are stuck behind a locked gate. The reward screen also does not pop. Closing underspire and re-entering does not solve the issue, though restarting the game does. This may be related to not having torches/lanterns before the battle, and then purchasing them.

Workaround is to restart game.

How often does this happen? When did it begin happening?
I’ve had this happen 3+ times. I sometimes buy lanterns on the 2nd boss, so frequently have 0 lanterns before facing Sapphirax.

Steps to make it happen again
Do not have any lanterns. Buy Lanterns. Fight a battle.
(Old: Do not have any torches/lanterns before a boss battle, and you buy a pack of torches or lanterns, then defeat the boss.)

Updated with further testing. It’s more likely related to lantern buying.

That just happend to me too. Bought lantern while having zero. Fought the fourth boss and won. Didn’t get the stone and the boss room didn’t clear.

Had to restart the game to update the map. Didn’t test if you could fight the boss again because I didnt’ want to possible lose anything.

I did, one week, but I used only a torch, not lantern, on the battle that glitched. When you start the battle, the game says that it is out of sync with the servers and restart required, the game restarts, and after restart - the battle is done, keystone found, gate unlocked.

What happened exactly when you won the battle? Did the game say “Victory”? Did you get to the reward screen or get an error message or anything like that?

The battle ended normally. Got the normal reward screen which showed the double items and the stone. But after I closed the reward screen, the map itself looked like the battle didn’t happen and only a new start of the whole game changed it.