Worst Deltarune bug ever

So I got Deltarune a few weeks ago and its now my 2nd favorite game of all time. BUT it has a very annoying bug: when deleting a finished save file and then starting a new one from the same file that you deleted, you can't continue the next chapter from the new file. This bug is so annoying and I wonder if anyone else has experienced this. If you know how to fix it (except deleting all the data from the game) please tell me.