Adventure Sync (Pokémon Go) can't be activated?

I have recently got a new phone (Huawei p smart Plus) and since then I can no longer enable Adventure Sync. Every time I click on "turn on", a window with charging indicator opens, but after that nothing happens anymore. I've been waiting 15 or more times, but the loading screen did not go away. Google Fit is installed. Does anyone know this problem and knows how to solve it?

Funny have the p smart + 2019 there everything works, sometimes the simplest question beforehand. Have you ever reinstalled it? Usually this solves all problems

Yes, I've already tried this: /

Sometimes it helps to clear the app's cache and reboot the smartphone.