Shift down problem

Does somebody know the cause of this? except for the first and second gear every time I want to shift down one gear I have to shift down twice, I already had it tuned by a local bike shop. The shift test without someone riding it seemed to be good, shifts all the way to biggest cog and goes down properly, but immediately when I rode it home, this down shifting problem occurs.

What could possibly be the causes? 🤔

(Sorry about the dirt and stuff, just got off the trails 😅)