Cannot rename bluetooth device on my mac
It looks like this is bug that show only up for few users.
There is no current solution, I event tried manually changing alias name in plist file but it is short term(until you connect next time).

There is more and more people that are having this issue.

In my company we use Macs mostly and I am the only one having this issue.
There are already some support questions opened on apples forum:
https://discussions.apple.com/thread/7904717
https://discussions.apple.com/thread/7927709

I have even spent 2 hours on phone with apple and they are saying it is not a bug XD