Why does my phone intermittently add Title and Subject attributes?

I have taken a lot of photos, over the past couple of days, using the default ‘Camera’ App that came with my Huawei Mobile phone. I have since uploaded these Photos to my Computer, via Google Photos.

I have noticed that a small minority of these Photographs have had random letters inserted into their ‘Title’ and ‘Subject’ attributes. These are viewable when I right click on the Photographs and head to Properties > Details:

The only pattern I have noticed is that these random letters only appear image files, where the photo was taken with the front facing camera. Even then, the `fbt’ appearance is still intermittent.

I have also looked for patterns in the below but could find nothing:

• Are attributes added for Landscape/Portrait images?
• Does a specific Day/Time affect whether attributes are added or not?
• Are attributes assigned, based on whether I am using WiFi or Mobile Data?
• Is there a link with File sizes?
• Could Google Photos be adding these entries?

It appears to be random. Has anyone else experienced this and/or have any idea what is causing this to occur?

Phone Details:

• Make and Model: Huawei Honor 10 Lite
• Model: HRY-LX1
• Android Version: 10
• EMUI: 10.0.0