Merging IP contacts with Email contacts

Your software
My Mautic version is: 3.0.1
My PHP version is: 7.3.21

Your problem
I’ve got an issue about merging contacts.

My website works with logged users, the users are able to access some pages, but the content is locked only for logged users.
At mautic I’m able to see contacts being created over their IP address, what is pretty correct, but after the account creation (providing an email) their track is not connect to the brand new contact.

These errors are showing in the log:
I got no logs on this.

Steps I have tried to fix the problem:
I really haven’t tried anything so far. I got no clue where to begin.