Weirdest fightcade toxicity I encountered

Did an ft3 against a C rank (I'm a B rank) a couple weeks back. In the first set he seemed really respectful/humble. No weird messages. Just stuff like "I got lucky there" or "haha" after a funny interaction. Won the set, said ggs and thought nothing of it.

Then came the second set. I think I was actually C rank at that time (I constantly fluctuate between B and C). It was an hour or so later and I ran into the same person again and won game 1 thinking nothing of it.

After I won the first game he said "now I will win".

Then for the rest of the set he started insulting my gameplay, teabagging and being all around unpleasant. Saying stuff like "stop running away" or "you're bad" or after a spicy denjin combo from me "I'm only a c rank you jobless virgin" (despite us both being c ranks at the time).

I still won the set 3-2 and I'm a bit disappointed in myself because I let it get to me a bit, but it was pretty funny looking back. It threw me off because I just wondered why they were so mad. What could have possibly happened in the hour between our first and second set? Was a different person playing? Or maybe they saw me as vulnerable since I was C rank now? Was so confused