Context
We have Emails Requests enabled with a Jira Service Management project. So, when one of our customers sends an email to our Support email address, it creates a ticket. That part works fine.
Problem
Except I realised that some (only some) tickets are created with our support email address support@company.com as Reporter, instead of the initial Sender, the client.
I can't figure out why sometimes the reporter is as expected, and sometimes it's our support email.
Expected behavior
Reporter field is filled with Sender (client) email every time.
What I checked
- The Incoming Mail section. Most advice on Internet suggest to set it up. But for JSM email requests it goes through JSM mail handler that is different. Here is a screenshot of our Incoming Mail settings:

- Project settings > Email requests > Manage Allow list (did not do anything)
- Project permissions are fine too (proved since it works in some cases)
- Customer permissions:


Ok, I did my best to explain it all. I did check similar issues here but could not find any fix unfortunately. I'm happy to add any additional info that would help.