Cunechan is asking all the right questions *High fives Cunechan* but, to be honest, this type of issue is next to impossible to fix without having a copy of the game project, there are so many variables involved, it could be event priority, it could be another plugin clashing with this one. I can give you suggestions, though, considering it works in a new event, it may be possible the save event plugin you use (I noticed the note tags in your screenshot) is causing the issue here, try removing those note tags and see if that helps. You can also check the frequency of the event , possibly making it the highest option may help, the higher you set the event frequency the quicker it is loaded in the map scene. It's all worth a try if that don't seem to work you can send me your project(or a smaller variant) and I can take a look.
[doublepost=1460051583,1459295343][/doublepost]
@MistyDay and I have figured out that this is a bug from yanfly's Mini Label plugin, a request for a bugfix has been submitted to yanfly.
I'm closing thread due to being solved-ish lol, if for any reason you'd like it re-opened please report this post. Thank you !