Undo Bug with Resource Bar

I would've added a video but my I got to fix my recording software.

Bug: When your resource bar is low, you recall back and then you buy items. When you undo those items your resource bar goes back to the point when you bought that item. Let's say you come back at 150 mana out of 1000 and buy a mana pot at 150 on the dot. You wait out the regen on the spawn platform and then decide you want to undo it, when you undo it, your mana is back at 150 and starts regenning from there.

Steps: Use mana Back Buy item(s) Undo them when mana is filled