Same problem.
SOLUTION:
The solution for me is always toremove updates for Google Play Services.
That will get my Forerunner 235 syncing with my Huawei P10 Lite again. However, then I get sign-in problems with the Play Store, which I eventually can resolve.
But the syncing problem will return at a later date most likely!
I have created a thread for this, that hopefully Garmin will notice.
a big Huawei devices problem