Dear Ableev,
We have Zabbix 6.0.17 running smoothly for more than 4 years upgraded from 4.0 to 5.0 than to 6.0.
Your incredible zbxtg.py has been sending both to the Bot and the group without any problem for many years.
Since two weeks time, it has started to not to send the messages to the group though that nothing has been changed so far.
I can send our settings which you would like to examine.
Please, help us in this matter.
Regards,
Nuri.