Low frame rate problem for no apparent reason. How do I troubleshoot this?

I was working on my program that normally runs at 120fps. Suddenly it began running at around 85 fps. It jumps occasionally between 70ish and 120ish but most of the time it fluxuates in the low 80’s. I restarted my computer etc etc etc… long story short I ended up removing everything I recently added, disconnecting all the ticks, begin play and construct events from ALL my actors, then totally REMOVED all the actors and inputs from my map so that NOTHING was being created at all… started with a fresh empty map with no actors and none of my blueprints are doing anything whatsoever… 50fps. If I create a new project it runs at 120 fps, but for some reason my project I’ve been working on has this low framerate problem. How do I figure out what is causing this? It can’t be graphical because there are literally no graphics being shown. I get no warnings. Is there a way to make it show what blueprints or processes are running that could be making it run slow?

Okay so I reverted to the default game mode and everything in my project. Base game mode, base player controller… everything default that comes with unreal and an empty map. It will run 120 fps in a tiny screen. But the bigger I make the screen, the framerate drops. Even though it is a completely empty map with NO graphics being shown. If I start a new third person project it runs 120fps at full screen. but for some reason It won’t on my project even though I’m using all default empty blueprints. I really don’t want to have to create a new project and export/import all my blueprints into it.

-Solved?- I tried making a blank project to migrate to, but it had the same problem at creation. So I had to specifically make a new third person game, remove all the content from it, and migrate all the content from my game into it. No more problem. I still have no idea what caused this or why a new blank project would have the problem, but I guess it’s working again. I’ll leave this here in case it will help someone somehow.