I have Relativity, Master Controller and Slower Relationship Decay https://www.modthesims.info/down...hp?t=564620&c=1

The only two issues I'm having are that the mood meter (tall gauge left of the motives) sometimes gets to full and stays that way, resulting in my sims standing around clapping and cheering nonstop. The other issue is fun won't go down below half. No idea why any of this is happening and I tried to search for answers before posting. Can someone help me?

What settings are you using in Relativity and what Flavor of the Slower Relationship Decay mod are you using? You might want to take a look at the Relativity FAQ. Almost sounds like conflicting settings between the two mods. Have you considered just using one of them?

I actually reinstalled fresh and tried with no mods or scripts and it's still happening.

What did you reinstall "fresh" a new town? Did you completely remove your mods folder and clear all caches?
Or did you try a clean folder game, i.e. renaming your original The Sims folder or putting it on your desktop, then starting a new game (the The Sims 3 game folder will recreate itself) to play a "clean/vanilla game where you could see if the problem still persists.
You are not giving much to go by here.

Fresh install means I reinstalled the game and deleted every Sims 3 directory, including the one in My Documents. I've done this twice.