Walk from where you are at. Preferably walk to a non-settlement internal cell.
Go someplace like homeplate "home plate is different than a normal settlement" and wait like 20-30 min real-time.
It is ok to sleep for a day or two in the middle of that 20-30 min.
other than that do nothing "I look at blank walls"
no crafting or the like.
At the end of the 20-30min save.
Exit the game and check again.
Make sure all t he Sim Settlements mods are current before doing all this.
I should be reduced considerably.
If not please post again. with the same type of screenshots.
Include the screen before that one that shows "unattached instances"
Good to see if you have been a bad-boy while we are at this.