So I was doing the quest “Rubee Problem” I believe I was on part 3. I just planted the Dynamite and I went back to the NPC and talked to her, and I “claimed the rewards” but I actually couldn’t because I didn’t have enough room in my inventory. So I clicked the button and it told me I didn’t have room but the camera still moved and the explosives still went off. Well when the explosives go off, they can kill Rubees and gives you XP if you do kill them. Because I couldn’t claim the rewards the first time because I had a full inventory, when I pressed the button to claim the rewards again, the camera moved again and the dynamite went off and killed Rubees giving me XP. I believe you can do this an unlimited number of times as long as your inventory is full. I didn’t farm it because I wanted to get XP legit. There wasn’t any errors in F9.
I hoped I could help. If you need any more information on this let me know.