Honestly, I'm struggling to understand what you're asking here.
The game's online rating systems work the same way they have since GT Sport's Beta in 2016.
You gain Driver Rating from finishing well in races and lose it from finishing poorly (it's a complex system, but you gain DR from players you beat and lose it to those who beat you; how much depends on the difference between your raw, numerical DR score).
You gain Sportsmanship Rating by driving cleanly, without hitting other drivers or solid track fixings or driving off the track, and you lose it if you drive off the track or hit other drivers or solid objects. You can get penalties without affecting SR and you can lose SR without getting penalties.
One complicating factor is that your SR can limit your DR: you cannot increase your DR rank above your SR rank, and if your SR rank falls more than 2.5 levels below your DR rank the game "resets" your DR rank to match.
If your DR is low and your SR is low, you're either driving off track, hitting things, and finishing poorly or finishing well but your poor SR is stopping your DR from rising.
It doesn't change between races (except when you quit a race; it won't update until after the race has finished for everyone else because your new DR depends on everyone else's), mid-race, or at any other time or for any other reason than what happened in your last race.
Perhaps you could provide video or screenshots of what you think the issue is? Your console records everything you see for up to an hour, so it's a simple task.