@mamc-: To troubleshoot the issue, please start by pressing the Volume Down and Side Keys together for around 10 seconds until the phone restarts, as this will refresh the device and address any temporary issues. Don't worry, this won't affect your personal data or settings. Now, head to Settings > Connections > Flight Mode, and toggle this off if applicable, followed by More connection settings > Nearby device scanning > On. I also recommend heading to Settings > Apps > Tap the 3 dots in the top right > Show System Apps > Bluetooth > Storage > Clear Cache > Clear Data. You should also make sure that your device is up to date by heading to Settings > Software Update > Download and Install.
Following these steps, please head back to Settings > Connections > Bluetooth > On > Place a Bluetooth device in pairing mode by following the manufacturers instructions, and select it from the list of available devices to complete the connection. Let me know how you get on.