User can't see field value

Just wonder if anyone has ever seen this before...

We are using CRM 2013 on premises. In one of the Org there are couple fields uses field security profiles. There is a "General User" field security profile that grants the default Business Unit Team with read privilege for all those fields.

But there is one user who can't read any of those field value (all comes up with asterisks).

I have tried to recreate her system user by point her system user to a dummy AD Account, and created a new system user record to link to her real AD. doesn't make a difference.

What I do notice is, there are 2 contacts exists in the same Org that has the same email address this user's.

Is it crazy to suspect that if the contacts have anything to do with this security issue? The system is clearly aware of the different contact and the user has the same email address, because on out going emails that is created by a Workflow is suppose to email the user but To field this type of email all set to the user as well as both of those 2 contacts...

I can't recreate the issue in our test environment, but then our test environment is currently on the latest update roll up and production is on a earlier build...

Any suggestions, ideas please?