After the release of season 3 I have tried to get the weekly challenges done, specifically the “Role mastery”, to win 3 games in each role in competitive or quickplay. I have now won atleast 5 games in each role, and it just says I have one 1 game in each role. And I have read it correctly: It’s in competitive role queue victories only.
I just found this in the “Known Bugs” Blue Tracker… So they are aware of it. 
- There is an issue with the “Role Mastery” Challenge not displaying the counts for each of the roles correctly.
- For example: When you complete three Tank role games, it will display 1 credit in each of the three different roles.
https://us.forums.blizzard.com/en/overwatch/t/overwatch-2-known-issues-february-7-2023/783293/3