Honor 20 Pro Bluetooth Connection with Vivoactive5 / Venu3s not useable

I had a vivosport for years but the battery died. So i decided to purchase a Venu3s.

Connecting the watch with my mobile, Honor 20pro with Android 10 takes a long time with many timeouts, after installing the new firmware the connection was worse than before.

My hope was that i have more success with the Vivoactive 5, but it was exactly the same.

No problems with an iphone, but the new garmin watches does not work with a Honor 20pro

I'm using Bluetooth for my headphones,  my car multimedia system and sound entertainment, no problem at all.

So I'm wondering what's different with Garmin watches.

I tried all the suggested solutions, but none of them helped.

I returned the devices.