Am I dumb or is smth wrong with the game?

Hi, I have played the game for almost 55hrs, completed almost everything the game has to offer, lvl 48 in Mable’s research, missing 10 colourful screws and like 30 side missions, and have never seen a shiny outside of the Mareep.

I use fast travel sporadically, mainly just walking around and I have a habit of catching everything I see to level up other pokemons faster without grinding the royale, but still no luck.

Is there a known bug or smth that could be preventing me from finding shinies?

Idk if it matter but I have never closed the game since I started it, in case there is any type of trigger of sorts.