Server version is 6.0.22.

edit: updated to 6.0.25 and the issue still persists

After troubleshooting OOM crashes for a customer, we found that the root cause seems to be a custom template the customer has created, that has a single master trapper item that receives JSON data with Zabbix Sender, and then there are some regular items and also a discovery rule with about 50 item prototypes and 7 trigger prototypes.
Basically the template doesn't contain anything crazy, just one single master trapper item that receives JSON, and dependent items that use JSONpath preprocessing steps to extract the needed data.

After we disabled the template, the memory utilization stabilised and the server wasn't experiencing any OOM crashes.
The template is currently attached to only 5 hosts.
Attaching screenshot of available memory, the arrow is pointing to the moment when the template was disabled.

I also tried to reproduce the issue, but was unsuccessful. I ran the test for 3 days having configured 6 hosts.

I will add server logs after crash once I get them from the customer.
Please ask for any other information that is required.