Although i'm not familiar with these guages I get the drift of what you're saying.
As an engineer i'd say report anything that your not happy with and we'll take a look at it.
Even of the answer to your tech log entry confirms what the book says at least you've done your bit.
I'd have thought an error code was pointing to something that needs looking at ?
Airbus would put this down as a Class 3 fault - fine for now, will be looked at under scheduled maintenance. No log book entry required.