Steps to reproduce:

1. Create a discovery rule host prototype
2. set the group prototype to any name
3. assign the template to any kind of platform query. I.e. Docker Swarm, Kubernetes, Cloud IaaS, VMWare

Result:

host reports:

Cannot create group: group with the same name "com.xxxx" already exists.
Cannot create group: group with the same name "com.xxxx.services" already exists.
Cannot create group: group with the same name "com.xxxx.ttapiv2" already exists.
Cannot create group: group with the same name "com.xxxx.ttchain_dev" already exists.
Cannot create group: group with the same name "com.xxxx.ttcollab" already exists.
Cannot create group: group with the same name "com.xxxx.ttchain" already exists.

Expected:

When a group prototype is specified and already exists, the host is added to the existing group

What makes this extra difficult is that it doesn't appear to have a workaround by creating a discovery which adds the discovered host to the specific group (i.e. not a group prototype) because prototype groups don't show up as a normal group.

ZBX-7898 has been open for 7 years for this, even though it looks to be trivial. It may be that because the ticket is so old, that the assignee has left and/or it has fallen of the radar. So no one is seeing my last comment to provide some development support to resolve this.

Hoping someone will see the new issue.