Incomplete sync

My new Vivosmart 4 doesn't sync completely with the Connect app.

I do get a green dot and it does sync heartrate, steps, minutes intensive training, calories, and stairs. However, activities and other information do not sync, and the white sync circle never shows up. If I try force a sync on my watch, I get the message that I should open the app on my phone. GPS also doesn't seem to work and if I change any settings for my watch in the app, that is also not synced.

The only way to get the other information to sync that I found is to remove the device from the app and reconnect it, but that is not a very good solution.

Does anyone have any suggestions?