iPad won't appear in 'Screen Mirroring' and 'Displays' pane in System Preferences

Hello folks. I encountered an issue while trying to use Sidecar. It just doesn't work. iPad won't appear in 'Screen Mirroring' and 'Displays' pane in System Preferences. I use Mac Mini M1 and iPad 8. Tried everything that Apple support website suggests:

• Wi-Fi, Bluetooth & Handoff are turned on both devices
• Both Mac and iPad are using the same Apple ID
• iPad is set as trusted when connecting it to a Mac
• My Apple ID uses two factor authentication
• My devices support Sidecar
• My devices use up-to-date software

Also I tried:

• Logging out and in iCloud on the iPad
• Connecting iPad via Lightning - Type-C cord to a Mac's Thunderbolt
• Rebooting both devices

None of this helped me. Please suggest me what can I try in order to fix this issue.

[Edited by Moderator]