Hi.
I write here because in the Slack channel to maintain it clean and avoid unquick questions, moreover, I thought some other could have the same problem.
Anyway, the fault is mine perhaps, I unpacked the prefab for a mistake, then I pressed CTRL + Z.
I regret of this: what happened is now Pun Instantiate says there's no Photon View component on the Player's root, but it is not, the component is attached!
In older versions of Unity, it didn't happen because there wasn't a severe/strict method, like the 2019's one, to modify the prefab.
Here's some screen.
Let me know.