Game not saving in campaign

I’m playing through the campaign after not playing in more than a year - social distancing because of COVID-19. I was on mission 8 in legendary when I picked up a couple days ago, and was able to return later in the day and pick up from my last checkpoint. Suddenly it stopped saving checkpoints, and the only way for me to advance is to beat the mission in one sitting and load the next level the next time I play. Is there a solution for this problem? I’m not sure if this has already been addressed since I got back into the game over a year after putting it down.

You can (I guess) check where is your data saving and check if it is corrupted or damaged.
Also you can check the settings, maybe the autosave is unable.
You can reinstall the game, idk this should help

Do you still see the “Checkpoint… Done” text?