I upgraded a couple of days ago, uploaded some photos over the last two days and now all of my 2020 images are on my external but not populating into LR.
Can someone advise please.
Uploaded? Do you mean imported?
Yes, sorry. I had imported some files yesterday - today 2015-2019 are all in LR. 2020 are all gone
In Lightroom Classic, click on All Photographs, turn off filters and then search for one of these photos by File name using the Filter Bar. Do you find the photo using this method?
No they do not show up then either.
Sometimes LrC looses track of the last catalog opened.
It is possible that the upgrade updated an older catalog.
Use your OS file manager to search for catalogs, investigate to see if a catalog with 2020 images in it exists.
I ended up reverting back to the previous version and sort of found them. But I will also try what you've suggested - thank you