Star Wars Jedi: Fallen Order
Zeffo: Tomb of Eilram. I was stuck at 96% after finding all collectables. In the square room with a circle in the center there are four alcoves with wind switches. Going into one of these alcoves and pulling the switch caused my map to jump to 100%. (Keep in mind I was done with the campaign at this point, so I definately had been in this alcove before.)
Kashyyyk: Imperial Refinery. I was stuck at 98% after finding all collectables. Immedietly after 100%ing all other areas on Kashyyyk, the Imperial Refinery jumped to 100%. I wasn't even in the Imperial Refinery at the time - I was in Origin Lake.
I'm not entirely sure whats going on, but if you are stumped on a region complete the rest of the planet. If that doesn't work, try running back through evey little area and interacting with everything.
I hope this helps.