Note for moderators:
I had accidentally put the wrong logs earlier and a mod though it was for 1.12.2, I already removed them and checked the other logs.

This happens when I go to my mine, mine for a while and come back home.
No idea if that's how to reproduce it currently, but it happens a lot. 
[It never happens when I'm trying to reproduce it though]

Expected:
Game ticks work normally

Result:
Game ticks freeze, still letting your character move, But blocks wont drop, entities wont move, redstone stops, game doens't save and more.
Also, if you try to exit the game, you'll be on "Saving Game" screen forever and the game will crash.

I'm still not completely sure how this happens, So I'm gonna include world download and logs. A bunch of logs.

I'll Record a video of me trying to reproduce it in my vanilla world shortly.