Tag Memory overrides itself

Hello everyone, I would like to ask your help about something with tags of memory type.
Randomly, some tags of memory type (it comes from udt, for example) overrides itself and the information or value desappears, staying in blank or null.

I have 6 instances (from udt's) are equals, but it only happens with 2 or 3.

I don't understand why.

I have reviewed many options, but i can't find the cause

Must be:

but by magic it becomes in:

Thank you for your help

The green circle indicates that the instance is overriding that value. That can only be done from the designer or via script. So unless you are configuring tags via a script....

Thank you for your answer, I hope it is not a bug of software...

But I have reviewed everything, I don't have any script over those tags (those what change magicly)

I can't find the cause and the solution.