Cannot send friend request and receive friend request. (Cannot solve by any method existed)

I Do my research. I using solution from support, other websites and none of them work. DO NOT LET ME RETURN MY WATCH AND GET A NEW ONE since I test iPhone X, iPhone Xs Max. AW3 & AW4. It's not device problems.

Area:

App-Activity

Summary:

Since the beta of WatchOS 5, Activity friends was gone. It's now official watchOS 5 and I still cannot send and receive any friend request.

Several of my friends have this issue too. It's not any pairing problem cause I using all help methods on Apple Help and also contact them. All unpairing, repairing, resetting cannot fix the problem.

I already give a bug reporter, however, I'm not in beta so not sure they care or not. I have this discussion here to see if anyone meet this problem. If you meet this one please reply and so Apple official people can see them.

For any APPLE officer/developer: Please must let the developer give a look at the problems. This is a very serious problem because the competition with friends is a major feature and not only me, but there are also lots of people cannot use it too.

Again, this may be an iCloud service problem! Please not only look at the SDK but also let the iClound team know!!! PLEASE!!! PLEASE!!!

Steps to Reproduce:

Open activity app

click Sharing view

click add button

put email and invite

Expected Results:

friend get the request, or I get the request from friends

Actual Results:

If I stay at the app, in a few minutes, it will give me alert "Share Activity" with "There was an error sending your Activity Sharing invitation. Try sending it again".

If I leave the app after I send, and back in a few minutes, the invitation that previously showing in sharing people view was gone.

Version/Build: all official version

watchOS 5.0.1

iOS12