Route 8 hidden grotto doesn't work

So essentially i messed with my computer time and it worked for a couple of times, at one point it froze on one of the pokemons and i cant use C on it or anything to fight it. It also wont change after time
I have redownloaded the game as well (core and patch) but its still the same
please help me fix this or tell me where else i can get delta snorlax

Have you reloaded a back up save? Also, you can save before entering and reset after entering until you get what you want

On that same save I went on to finish the game. I don’t want to start over again…
I just want to restart the internal clock

Loading a backup save is just going to the last time (or up to the third last instance) you’ve saved. Say you saved in front of a pokemon center, got this problem, then saved. You can load a backup to go back to the pokemon center. If you saved more than 3 times, a backup may not work and you may have to reinstall the core.

Guide on how to load backups here: