In Material Preview Mode model become grey

Idk why my model become grey like this in Material Preview Mode, it wasn’t like this before.

if in Rendered Preview Mode the model looks like this, how to turn back my model can be seen again?

Here my model Watershed Model

Weird, it actually works as intended when I open it, is your world lighting/scene lights or similar things on?

World lighting/scene light? I think I don’t change anything over there. Because I didn’t know what to do, in the end I gave up and “Load Factory Settings”. But didn’t change Material Preview Mode.