After completing the Bonus Campaign on Normal Mode, the Rexxar portrait did not illuminate and does not show the campaign as being completed. The Frozen Throne portrait does not show the Bonus Campaign as completed either. All other campaigns show as completed and have their portraits unlocked.
I reloaded the last save on the final act, completed the mission again, and nothing. On both completions, I did not skip any cinematics, I did not use any cheats, and I fully watched the credits.
Restarting WC3:Reforged did not show any completion status. Loading the last save in the campaign and completing the bonus campaign a third time still yielded no result.
If it’s because I saved throughout the campaign and loaded, then half of the other campaign completions in theory would be affected as well. Those showed completion without fail. No need to manually resolve.