I have the "Clear Stage 15 or High of San Devil's Necropolis 3 Times" Advance Quest.

From the adv quest menu:

1. Click go
2. Click Multi Battle
3. Set to 3
4. Click Start Backgroun Multi Battle

I have left it for over an hour, my laptop gets very hot, but it never finishes.

I can clear the stage in seconds, so was expecting 3 battles to a minute, maybe 2.

Player ID: um155834017 | 149898087

Device: MacOS