I posted a note about my problem of AP+ three days ago(first picture) , and I’ve solved it yesterday. This post may help you.
I tried to offload the game from Setting->storage (second picture) and downloaded it again. After doing this, I found a flight that I have not flied. I clicked the trash bottom and entered the ES or other server to taxi for some time. And then I returned to Main menu. And then AP+ could work again.
I used our college’s WiFi to play the game and the WiFi’s speed was very low. I also went to B1 floor where had no WiFi connection. So the connection between device and server was bad. Something went stuck at that time. This maybe the problem.
The last picture is the screenshot after offloading and downloading the game again.
Device: iPhone 14
Operating system: iOS 18.4.1