When he coached Sassuolo, his tactics were already pretty and progressive but he was also pretty easily found out and countered.
I don't watch Brighton much, I'm sure he's improved accumulating experience in Ukraine and PL, but down here he's still framed as a bit of a hipster coach, exciting but lacking substance for a club that has to deliver trophies.
Probably unjust but you can sense the prejudice.
While for smaller clubs like Lazio, with the relatively high profile career he's having, he's already beyond their reach.