We added a feature this years so flagging an already reviewed post is blocked:
https://github.com/discourse/discourse/commit/fadb2b7157d744226c85eccba92af1cbd2924c43
It can be tweaked with the setting cooldown hours until reflag @Fares_Droubi1.
However the error message is wrong… Did we regress here @Roman_Rizzi / @featheredtoast ?