For 2 years Safari Offline Reading list is broken. For me it works 30% of the time and I have no idea what causes it. All devices are on the same iCloud account. I’ve logged in, logged out, reset etc etc. Even had 12 months of support calls with Apple and this crappy system still doesn’t work reliably. Sometimes it saves offline. Sometimes it syncs across devices. Most the time it doesn’t. Just like the Text Replacement fiasco when will Apple fix this simple thing once and for all. To test. Save a page on your iPad to the reading list. Wait a few minutes and turn your ipad and iPhone to flight mode. Then go the reading list on your ipad and iphone and try and view the saved page.