After the hotfix update game still gets stuck after applying upgrades. When only solution is to quit the game, restart and losing your progress. Should be fixed but certainly is not.
Playing on a Series S, could reproduce after adjusting fuel, finishing race, after race applying upgrades where it got stuck. Happens in Modern Tour Premium Performance.
Exactly the same issues as at this closed task: Stability - Game may hang on applying upgrades and does not save career mode progress (1608827) - #932 by BobGT3000