We use macros with context in name of item prototypes.

example name of item:

{$ABC:"{#SNMPINDEX}"}

example macro:

{$ABC:1} >> itemname1

After Update of Zabbix from 5.0.4 over 5.0.28 to 6.0.9 result is {$ABC:"1"} and not itemname1 anymore.

We don't see relevant differences in documentation, so think it should work in v6 too.
https://www.zabbix.com/documentation/5.0/en/manual/config/macros/user_macros_context
https://www.zabbix.com/documentation/6.0/en/manual/config/macros/user_macros_context

Could you help?