I noticed about eight hours ago that I had a bunch of upvotes, seemingly on just about every post I had made. I'm not surprised those were taken away by an automated check. However, I went from 1494 rep on Monday, to 1639 with the upvotes, down to 1401 now. I'm not that stressed about losing a little rep, but I thought I'd bring it up and see if there was a reason why my rep reset to well before the upvote surge.
Under normal circumstances your reputation doesn't go down when a post is deleted. This means that your "headline" figure can drift away from your "real" reputation.
When someone is the victim of a serial voter - either down-votes or, in your case, up-votes the vote fraud script kicks in and removes the fraudulent votes. It also recalculates the reputation of both parties. At this point you now get to see your true reputation.
You can check what the true figure is by using https://diy.stackexchange.com/reputation.
There's also a button on the bottom of this page to trigger the recalculation.