After spending a couple of hours with the user, we decided to just use the work around of using Firefox. Today the user emailed me that the issue was caused by a content blocker they had installed (Firefox Focus) on their iPhone. They removed the content blocker and the Glide app started working. Reinstalled the the content blocker and then using some settings they were able to whitelist my app’s address and now the app works.
The content blocker had to have the option Content turned on to cause the app to go offline. The content blocker somehow integrates with Safari.
Not sure why content blocking causes this but at least there is a work around.