Steps to reproduce:

1. Why Host groups with identical names are allowed?
2. What was the idea behind this?
3. Host Groups logically should be as unique identifiers (as host name, as item key)
4. Now I got Zabbix API JSON string with Hosts and related Groups, but because of "allowed duplicates" I will need to implement ugly logic to search for and automatically rename duplicate names.
5. With duplicate group names I can't simply take Zabbix API output and build build new JSON for LLD rule, because it will throw error that item prototype already exists.
6. Consider making host groups as unique identifiers. There seem to be no benefit of allowing duplicates. This only mess up things.
7. The existing duplicates (which are already added to db) may stay, but "new Host Group add" function could further not allow making duplicate host groups.

Result:
See screenshot...
See log file...
See memory dump...
Expected:
See screenshot....
See attached patch file...