Rating jumped for no reason

I don't know. Maybe if the rating thought of you as a means of escape, then...

I'm just yanking your hair @withnail42. With your rating now 1555, it's a bit difficult to tell. Perhaps one of your opponents had cheated and you were later rewarded or reimbursed some points

Also, you still get points even if your opponent was rated lower than you, especially with correspondence chess. Did you check if any game had ended, with you the winner?

No games have ended within the last 24 hours. It could have been someone cheating, I guess. If that's the case I'm not sure why my highest rating still says 1549. Wierd.

you can see the reason if you go to your archive. Can't say more than that without going against the forum rules.

But you have highlighted what looks like a minor glitch - when they manually refund points it doesn't seem to have a knock-on effect to your "highest rating"

Different algorithm that checks for highest, I expect.

I don't know... these guys usually pay special care to detail. It could be that they decided - because you didn't really beat the opponent, it can't then be said that it was your best win. I suppose to put this to the test we'd have to view instances where the circumstances varied.

Though I once had my tactics ratings readjusted after a slight glitch and then too my highest rating stat did not add up. This was a long time ago, of course. I could be mistaken.