External hard-drive thinks it's internal...

[rexone]

This is weird.
Used Disc Utility to reformat a new 4Tb Seagate Expansion drive yesterday to use as my Lightroom library & have encountered this.
This definitely external USB hard-drive is being recognised as an internal drive after reformatting.

Anyone know...
a) - what has caused this
b) - if it's a problem or if I should just ignore it

Late 2014 27" Retina iMac running 10.11.6

 

[Fishrrman]

Does the drive still appear on the desktop?
Can you access it as required?
Can you mount it and dismount it?
Can you connect it, disconnect it?

If it "performs normally", I'd just use it and not worry about Disk Utility...