Sometimes I get Strength=[10,true,true] and... predictably, the game crashes whenever I do anything that touches Strength afterwards (training or pushing rocks, doesn't matter). I don't know what causes it, but happened on two separate occasions. One was on the first day, I'd picked a mentor, decided to explore (since with that mentor at least choosing to get a tour softlocks you when you get to the Fight Club 'cause Street Fighter Girl wants to talk to him for talking bad about her sister but she has no dialogue for that part... or at least, that's what I'm guessing is the problem), and at some point (I didn't know to pay attention then) I got the odd Strength=[10,true,true] and when I went train the game crashed. Second time I beat the guy that looks like the FRLG Rival (in D-rank area 3) and I got the exact same Stat issue. Tested to see if pushing a rock would fix or crash, and crash the game did.
Edit: when I re-loaded the save after second instance when I checked my stats I still had the problematic Stat, so... I really don't know what causes it. Sorry...
Edit 2: did some testing, and... at least when you do things that touch other stats, the game doesn't crash? It doesn't fix it, but at least it doesn't crash, so you can still study and (presumably) do your homework and everything else while your Strength stat is glitched.