It's very likely that the photos are counting against your storage quota because, due to some reason, they were upload as "original quality" (or something like that) instead as "high quality"
If you have a free/consumer account you could check what app is using the storage quota in https://one.google.com/storage
NOTE: The above link only works for ...
Press Ctrl K in document A at the desired position and instead of typing or pasting in a URL into the dialog box that appears, run a search for document B, select it and click Apply. (Source: Link Between Documents in Google Drive).
Had the same problem, found the solution here :
It's this little switch that caused the whole "Offline" problem (in the parameters of Google Docs here but can be in any Google app) :
It was on, an the moment I switched it off, everything came back.