Ergh, not sure why... but sometimes, randomly, when I am an OP in my room, match that I play ends and I press space, new round starts, and suddenly after just a second the game jumps into a frame of the past round for both players.

For exampe, in a simple way:

*First frame(s)*
Player A - crouched.
Player B - jumped.
*Second frame(s)*
Player A - twisted.
Player B - planked.
*Third frame(s)*
Player A - DQ.
Player B - won.

*New round starts*
*1 second after*
Player A - twisted.
Player B - planked.
(just like in the last round - Second frame(s))

So basically it jumps into one of the frames of the last round for both players and round is to continue from there, and then I have to /reset. It happens randomly, ever 3-6 rounds.

I am not sure why is this happening, and/or is there a way to manipulate this and/or purposely recreate this?

Old bug, and one that we're not entirely sure why it happens. If someone could forcibly recreate it on a reliable basis then it could be cured, as it stands it too random to nail down.

From what I've observed, it only happens in player-made rooms. Perhaps the host's internet can't handle the sudden resets that happen at the end of a match, so it reverts back to the first move the player(s) make in the previous game?

Game isn't hosted peer to peer, it's client server so it'd have to be a server issue causing it rather than a client one.