First, there is no need to use "PKHaX" when editing save files unless you are looking to edit values without some guardrails.
If you've corrupted your save file with cheats, then PKHeX is unable to load your file. It uses heuristics to check if a given file is somewhat valid, and your party data is not stored correctly.
By forcing the data to be correct (changing offset 0x2F2F to be 0xFF so that the Party List is valid), your save file loads, but honestly you have zero in-game progress.
Start a new game, and try with the development build.
https://projectpokemon.org/home/files/file/2445-pkhex-development-build/