as life happens, i stumbled upon the answer shortly after the above:
v1awifi is for the Galaxy Note Pro 12.2 (the one with the pen, usually white case)
v2awifi is for the Galaxy Tab Pro 12.2 (the one without pen, usually black case)
the confusion stems from search engine unfriendly naming, they are both tab(let)s and marketed as pro.
the correct model number is printed on the back of the device. you may have accidentally (?) flashed v1awifi instead of v2awifi. it seems the devices are fairly cross compatible.
Here is a good review of the specs for both:
Note Pro (v1awifi - SM-
P900):
https://www.gsmarena.com/samsung_galaxy_note_pro_12_2-6048.php
It has the S-Pen slot at the outside right side at the top if you are in landscape mode with the camera at the top.
Tab Pro (v2awif - SM-
T900i):
https://www.gsmarena.com/samsung_galaxy_tab_pro_12_2-6212.php
It has no S-Pen.
You're right , the easiest way to distinguish is if you have the S-Pen slot and hopefully still have the pen, it is definitively a
Note Pro.
They both have the same chipset and graphics chip, but the Note Pro (SM-P900) has additional code and circuitry to accommodate the S-Pen (first gen s-pen, it is not powered but is a passive device.) Whether or not that impacts anything would probably depend on the applications you run, but generally it is better sticking with the correct model operating system.
You are correct, if you have one model, and it is saying it is the other model, more than likely you flashed the wrong version of recovery software (TWRP 3.1.1 is highly recommended, v3.2.1 displays errors that
may affect your backups). You can fix that by just re-installing the corrected version over the existing one using something like Odin to install it.
Always make sure you have good backups before doing a flash!
