I was playing around with rep recalc on Stack Overflow a few days ago, I had 555 rep before recalc and 545 after. Later on I got an accepted answer (2 days ago, on Saturday) and my rep went up to 570, as if the recalc never happened. Is this the expected behaviour?
A reputation recalc is not persistent in the sense that it simply sets your reputation to the calculation at the time of the recalc. Ways this can quickly break include the following, which are rare but do happen now and then:
If you recalc mid-day to clear some vote reputation on answers you just deleted, you could end up earning only 170 reputation max that day because you're capped from the +30. You'll need to recalc the next day to fix it.
If you recalc, and then whatever you lost ends up undeleted, then you'll need a new recalc to get it back. This is what I assume happened here - you had a +10 source that was deleted, then it got undeleted, which would first withdraw the +10 (so it looks like minus 10), then it would add it back on the next recalc.
In essence, the reputation recalc doesn't foresee the future changes that could happen to de-sync your reputation again, so it can only handle whatever desyncs are currently present.