So this has only happened to me once back when I was playing two years ago, but coming back to the game only a week ago, it's happened to me 3 time today, and I've also witnessed it happen to another.

The player's global rank would jump to the person who just beat them, but would be off by one, and the mod rank sometimes as well.

Any idea when there will be a fix for this? It's particularly annoying being someone who watches their rank to determine how well they're doing just disappear in a seconds.

ex: My rank personally has dropped from 800 to 4k in a day, and my mod aikido rank (something I pride myself on) has dropped from 80 to 700.

It usually happens to me when I get streaked but winning/losing once shouldn't do that.
Nonetheless, I'm pretty sure it's part of the game.

I think this happened due to the elo you have, the elo of the other person and the general elo for the particular rank itself.