Hello my run for the TPE Glitchless got rejected because I "Did not true reset" But I removed all my games files, including the saves one in appdata/local/UNDERTALE before doing my run, so I'm wondering how it is possible ? Would a moderator be able to explain to me why this reject ? I'm not contesting it, but I just don't understand why it got rejected.

I've just looked at your run. When you reach Flowey, he says "Don't you have anything better to do?" implying that you've reached and interacted with him on that save file.

If you haven't already disconnected the game from Steam, do that, otherwise I'm pretty sure it will pull data from Steam Cloud.

^ do that

Also the game auto saves at certain points in the game even if you don't save. I had a run rejected recently cause I failed a run and thought because I didn't save I was in the clear.

it only loads the autosave if you die tho. reloading the game will set you back to your last regular save

there is a autosave right as you spawn

And not all auto saves respond to deaths only.

the only autosave that has nothing to do with dying is the one after the asriel fight

the autosaves are written in the file, and even if you reset, the game still knows you played it at some point and reset at some random time.