So Ive looked into this and the reason it does this is... Interesting! Since I use a custom icon for the executable, it slightly changes the filesize of the executable and windows flags this as a false positive threat. The only real fix for it would be going back to the default renpy icon...
Hmm, I think I just got unlucky with this one and my windows decided to detain the executable (I play a few visual novels and by a few I mean Sixteen lmao) this is the only time it has happened, and I was able to reclaim the executable when I did a little bit of digging. Maybe put in a warning, or ask other VN creators about it?