You may want to raise this as a support ticket.
This field (along with most) is ultimately being populated by the inventory scanner (LDISCN32.EXE and it's related items)
If the Inventory scanner can't / doesn't detect those devices as being portables for some reason, it'll need to go to dev eventually to be resolved (both the "why is this not being detected" and "what needs to be done to get those devices to be detected").
Most likely a combination of hardware vendor shenanigans and OS stuff (guessing that the various attributes we're looking for to identify "this is a laptop" aren't what we expect them to be). May require debugging stuff from dev - that's not something that will be able to be handled on the community.
Does that help?
One of the main things we use to designate something as portable is if we can find a battery. It may be worth checking the device's inventory to see if a battery is indeed picked up.
That said, as phoffmann mentioned, this will likely take a support case to diagnose fully and resolve. But getting that battery info could help get things started faster.
Thanks, for the replies. I will open a case with support to see what they can do for me. I figured that was what I was going to have to do, just wanted to make sure that there wasn't something else first.