Open Join "confuses" 2 different devices as one

I have a 2018 Samsung J6 plus and a J7 prime from 2017; when renaming, I realized I couldn't tell them apart, and when I re-named the J6 from the samsung real model name to just "J6" to identify it easier, I realized the J7 got renamed to "J6" as well. Is there a way to fix this?

The resulting behaviour is quite annoying; notifications are sent to both of them, I cannot share files between them nor mirror notifications reliably, etc.

Thanks,
Gabe

PS: I did search for other thread as I wouldn't think I'm the 1st one with this issue, but I couldn't find any.