Don't your first few games on Chess.com experience the same as well? This is because of rating deviations - Chess.com cannot establish your opponent's rating accurately in the first few games, so the rating fluctuations are large initially.
When I first signed up on this site a few years ago, I placed my playing ability around the intermediate range as I wasn't entirely sure of the playing strength of the community. Apparently, as it had proven, my rating shot up (and I eventually realised that I was playing at a higher level than what I had imagined my opponents' playing strength would be).
Your opponent probably played better than you (or maybe benefitted from an unforced error of yours), but Chess.com does not distinguish between different causes of wins, losses or draws - a win is a win regardless of whether it is a win by checkmate, timeout, disconnection of opponent etc.
In the long run, as your opponent's games history starts to build up, Chess.com will have a "reference base" to his performances (win/loss/draw), and as such, the rating gains or losses post-game will no longer be high.
When i was playing chess with a person rated 520 they joined yesterday march 27 2024, then i lost i lost 11 or 10 points but the got 183 pints higher which got them to 700+ and im so confused and i think this is unfair please someone explain thank u