My setup
Iphone X ios 11.3.1
Windows 10 iTunes 12.7.4
14,000 photos and videos in 95 albums
First off, thanks to everybody who has been contributing to this conversation with ideas and workarounds, its been a couple of months now and we only have each other to help out, Apple are nowhere to be seen.
Im not really that tech savvy, the downgrade to 12.7.3 didnt work for me as my PC wouldnt open it as itunes library was created in a later version and i wasnt confident enough to mess with things i didnt really understand. I had already messed with various fixes and ended up losing over half my photos off my phone. Today I got them all back without doing anything too invasive or technical.
Just did a very succesful sync, heres what I did.
Uninstalled itunes on PC
Deleted ipod photo cache in My Pictures
Restarted PC
Reinstalled itunes 12.7.4 from Apple website
On my iPhone (camera roll empty) I activated "icloud photo library" in Settings - Photos. (It gave the warning all photos synced via itunes would be removed) This is what i wanted. So it was a case of tricking the phone into deleting everything synced! I went to "Collections" on the phone and watched live as everything was deleted, took a couple of minutes. Then went straight back to settings and turned "Icloud photo library" off. This was the only way I could remove synced photos off the phone and just unchecking the sync button in itunes didnt remove them, it removed the folders in "albums" but the pictures still existed in "collections".
I now i have an iphone with no synced photos on and a PC with a fresh install of latest iTunes and NO ipod photo cache.
I selected all photos in the sync settings on itunes and hit Sync! It worked at normal speed, took about 45 minutes to CORRECTLY sync over 14,000 photos and videos (25GB).
I am very happy to have everything back on but i have no doubt at all that next time i try to do it it will go back to being stuck reading photos in one of these loops that people are talking about. I think the success in this is that its a fresh sync with fresh itunes with fresh cache and freshly emptied iphone!
Ill now just wait until Apple fix there mess.
I dont really understand everything guys, i may use the incorrect terminology but i came oon here today to share this with you as its an easy was to do a full photo sync without having to rollback software or mess too deep into things that you dont understand (like me!) I think the big thing was to actually get iphone to delete the synced pictures, and clearing the cache on PC.
Unsure what parts of my steps were neccessary and unneccessary but if you have messed with various fixes over the weeks and messed up youre photo library like me this was a non destructive way to do a fresh onetime sync to get everything back. (dont sync a folder at a time... i think you only get one fresh sync so make it count! Do everything in one go...
Hope ive explained it OK and maybe it helps a little.