Just about drove me nuts spending days searching the issue without results and changing service worker code over and over again. I have made several web apps - a few for companies that need offline use. They were all working when opening the apps from Home Screen without an internet connection, and then suddenly I noticed this weekend that one of my personal apps (lyric.cc) would not load when I was around a campfire with my guitar, in the middle of a field with family. I connected my phone hotspot and got it going and once the app was open, it worked when I turned the hotspot off.
Very frustrating as trying to figure out what was going on consumed me for the whole time and then this morning I checked all the other PWA’s I have built and none worked when I turned off the internet - even the 2 that I built for a couple of companies that use them in areas where there is not internet, at times. Surprisingly, the only Web App of mine that opened, was one that i havent updated to Service Worker, from the older AppCache that I used to use and found dependable.
Fortunately before I started tearing my code apart today trying to figure it out - I put the search words in that got me to a REDDIT post that started 4 months ago, and had replies from 27 days ago and then several hours ago a response that the issue is still there in IOS 14.7.1. Low and behold - that is the version my ipad and iPhone are on.
Frustrating to say the least. But at least I wont waste needless hours or days of frustration because I can’t fix it. Hopefully it is something that gets resolved soon by Apple. Meantime I will warn my commercial clients not to update their iPads IOS until further notice.
*** This bug has been marked as a duplicate of bug 225083 ***