"Can't load project." error on iOS for shared project

I have created a project on my Android phone and have sent the shared link to my friend that has an iOS phone. He was able to see the project at first, but now gets the “Can’t load project.” error message. I am sure that the project is in run mode on my phone. He installed Blynk on his iPhone two days ago, so he’s running a current version.

This bug seems to be the same as this one (that’s been fixed earlier in the year): App is unavailable

FIXED: it was his works internet filter.