Firstly go to your device Settings > About device then change your device name from "Edit" option above then try.
Even if it's not resolved then go to your device Settings > Apps > Perform "Show system apps" from rightest "3 dots" above then find out "Bluetooth" app from search box and go to "Bluetooth" > Storage then perform "Clear catch" and "Clear data" & then try again. Screenshots below for last instructions...
