This isn't a facetious question
Although your files are in iCloud, have they been removed and put back by anything other than LumaFusion?
If for example you've deleted them from iCloud to make some space, done some other stuff, deleted that and then brought them back into iCloud, although they are back in iCloud and you can see them etc etc IOS will have given them a different filename internally and that's why LF knows it needs them but can't see them
Thanks Dave, I understand. Sadly no. I thought it was maybe because they weren’t on my iPad, but in cloud. I have downloaded the file by entering edit in photos that triggers the download then once downloaded, pressed cancel edit to exit edit mode. The file is then physically in my phots on my device. Didn’t work