After the advice from @SGaist I started to experiment a bit with settings of the build steps: problem disappeared after I did these three steps one by one (after each I checked if the problem is gone - it disappeared after the last step:

turning off QML debugging and profiling switch (default was "leave default", effective call showed CONFIG+=qml_debug now it is CONFIG-=) turning off QtQuick compiler (default was "leave default, effective call showed CONFIG+=qtquickcompiler now it is CONFIG-=) deleting shadow build folders (I do it routinely once a week or so anyway).

Now the problem is gone, I am marking the topic as "solved".

Hi and welcome to devnet,

Did you try with macdeplyoqt ?

Thanks for the feedback and link !

@wesblake Hello,
Using the information you've provided I've managed to upload my package to the appstore using Transporter, however even after inserting com.apple.application-identifier and com.apple.developer.team-identifier to my .entitlements file, I still get "Not Available for Testing" status in TestFlight.

Could you share any other entries in the entitlements file, or any other leads to resolve this issue?

Hi,

Even if not through the App Store, it's better to sign your application so people know where it comes from.

What's not clear is why would you need to do a second signing of your application with e.g. a Symantec certificate. What did make you think that ?