After trying the Rook Challenge, I exited back to the world and became... floaty? Jumps would send me high to the sky and would float down ... often to the middle of the air and just stop.
Ever since Rook Challenge (which I tried the moment this test started, the physics have remained very messed up for me. Stuck character animation. Jumps cause me to fly very high and then gently float down. Does not allow me to go down elevations (so if I climb into trees, for example, and try to walk off a brach, I just keep walking on air.
I thought it might have been because of a shoddy connection last night and lack... but I have a good connection today.
Same issue in both Firefox and Safari.
Removed all cookies (because you never know) but issues remains.
Returned to Rook's Challenge to see if that my fix it. Physics DID return to normal while there. Have not left challenge yet to see if if fixes everything. POTENTIALLY what happened was I gave up on the challenge last time in the middle of being hit by rock and flying backward and that messed things up.