Create new record does not update field from other table

I have a table (Reminder) linked to another table (Devices) in a 1 to many relationships (1 device can have many reminders but a reminder only one device). I have created a form who updates 2 tables:
1- Creates a record in the reminder table
2- Creates a record in the reminder-log table (register all the changes done to the reminder object).

When I push the create reminder button of the form, records are created in both tables but the value “device” is only updated in the first table (reminder). In the reminder-log table, only fields not coming from another table but reminder one are updated. Fields coming from a relationship and selected via combo selector are not updated.

I have another form for editing reminder tables. In this case the same process (update de reminder table + create a new record in the reminder-log table is working fine with the mentioned device field being updated in both tables.

Any thoughts? thanks. Antonio