Dumb question about rating. Lost -381 in a single lose wtf

Is this normal? Or its some mechanism to prevent noob players to "luckily" grind? I am a really bad player, I got my ups and downs, today I got 4-win in a row with me "smurfing" because I learned the mechanic to stop the character (press the opposited bottom) so now I can hit my shots. Really good adr and kda and all but I noticed something.

Every win I get, the next match I was going to lose more points. I got 4w and was about to lose -451 points but I got a tie and lose some points so I played again and lost. Now this time was -381. I know this doesnt matter for premier but I was top kda and adr/dmg and was playing against a closed team with everyone having more premier points than me and still lose -381. I just dont understand how it works.

If I would guess its a mechanism to prevent noob players to get carried by better players or something like that. So if someone with a high skill pick a new acc and carry a noob, when the noob lose he will lose a lot of points. Is this correct?