Message confirms the the export was succesful but cannot find the files anywhere in any album. Please help. I can share directly to social media but unable to save photos to phone or camer roll. I have an iPhone 10 and already resinstalled LR Mobile app.
So you are having problems saving to Camera Roll as well as Files if I understand it correctly. If you look into e.g. Recent in the Camera Roll, you don't find any of the images that you've exported? Are you using Share to... when running into this or are you using Export to Camera Roll, Export to Files or Export As...?
What images are you trying to share when you run into this issue? Does it occur with e.g. JPG from the device or are you having issues with e.g. RAW images?