Message of successful import, but actually no photo imported

Hello, i use web browser Version of lightroom by Chrome on a Windows 10 i successusfly worked before in this way but now when i try to import the photos, it does all the upload process

and says that the photos are successfully updated, but when i press to "continue" just 2 photo of 90 are actually imported, about the other 88 it's impossibile to find them, if i try again in another album same things, if i try again in the same album it tells me that i'm duplicating, like they are already present, but actually no photo of the 88 present.

Somebody can give me an explication and help please?

Thank you