Some Contacts Disappearing during normall use

Your software

My Mautic version is:2.15

My PHP version is:7.2

Your problem

My problem is: Some Contacts are disappearing during normal use of Mautic. We send regular newsletter that goes out daily to three main contact segments. One of the segments is very small (the contact in it are paying) and very often one or more contacts from this segment complain that they have stopped receiving the email. Upon receiving such complain we check and it turns out that this particular contact is missing in Mautic, like it has never been there.

We had such occasion last week. We created the contact again, manually. Then, 3 days later, the contact has disappeared again….

Any idea what can be causing this?

These errors are showing in the log: Nothing relevant is found in the log.

Steps I have tried to fix the problem: I cannot figure it out.

I am currently experiencing the same issue, did you ever find a resolution?

Hi, I believe I resolved it by turning off the option for identifying contacts based on IP address.
Since then I have not come across this issue again.