Hi, I want to add that Ive experienced the same bug. I got the fruit the same day I got 200 items. It happened once before so I had to reload. I didnt consume the fruit until I got home. Thought I was close enough to my bed, but apparently not. I can only move forward in one direction after consuming said fruit.
Currently it is summer 19 for me.
A few hours before this happened, I took care of crops, went to my barn, then to my 2nd barn to load up cheeses/milks/etc. After I did my morning task, i decided to go and pop open some chests, so I went to the black smith. I have quite a few chests (I think 89 pirate ones or something) so I do it until I fill up my inventory. Once full, I go to the museum and drop stuff off. The other stuff thats a duplicate goes into a chest.
now using the Stamina fruit puts me to 717 stamina as well.
Other info: Version 1.2-1242
Platform: Steam PC
Occurrence: seems to happen if i just consume the fruit.
Game Date: Year two summer 19.