UPDATE: now it works. I didn't change anything. I just had to wait. I use latest version of everything, I was sure problem is on TestFlight side

thank you. this should be the accepted answer (+ of course clean and build)

I've just created external group for testing and added myself and it's working for me too. Thanks.

it's not related to just One Signal. I don't use it and have this problem. My app only contains widget extensions

thank you, I've tried to set all possible params for renderingMode, nothing helped. The code you posted is not working either, but thank you anyway.

I forgot to add that widgets are not affected.