Perform "Interactive checks" for "Bluetooth" first, through Samsung Members app. It's an official means of hardware checking.
To do that, go to Samsung Member's homepage and follow the screenshots below...
If it looks OK after checking then go to device Settings > Apps then click on vertical "3 dots" right sided above then tap on "Show system apps" and find out "Bluetooth" app from search box then tap on "Bluetooth" then go to "Storage" then perform "Clear cache" and "Clear data" and then try.
Even if it doesn't work then perform "Reset network settings" from device Settings > General management > Reset > then "Reset network settings" only and then try.
Even not, then perform a factory reset on your device. Even not, then take your device for servicing to the Samsung authorised service centre.
