Computer-to-Mac — Connection Issues
If you're unable to connect your devices via Ethernet, Thunderbolt, and Manual WiFi when using Luna in Computer-to-Mac mode, it's possible that you've encountered a known issue. This issue forces the secondary Mac's connection filter to automatically change to an incompatible connection type without any input from the user.
Please note that this workaround will not be successful for everyone. If you find the following steps do not work for you, please reach out directly to our Support team for further troubleshooting help.
Step 1
If you're in PC-to-Mac or Mac-to-Mac mode, confirm that your primary device's connection filter is set to "Allow any network interface (default)." After confirming this setting is in place, try connecting your devices via Thunderbolt or Ethernet, as well as Manual WiFi. Be sure to set up the Thunderbolt and Ethernet connection prior to launching the Luna applications.
Mac Connection Filter
Open the primary Luna application and go to Preferences > Mac-to-Mac to change this setting.
PC Connection Filter
Open the primary Luna application and go to Preferences > Connectivity to change this setting. 
Step 2
If you're not able to connect, close the Luna primary and secondary applications. On the secondary Mac, open Finder and select Go > Go to Folder.
Paste ~/Library/Application Support/astropad/LunaSecondary/ in the search field that pops up and press "Enter" on the keyboard to search.
Step 3
Step 3In the Luna Secondary folder, select and delete all of the files that include state_sync in the title.
Once these files have been deleted, it should reset your secondary application settings and force the primary and secondary devices to re-pair and connect.
After this has been completed, relaunch the primary and secondary Luna applications and try connecting again. You should be able to see a stable connection between your devices with Luna in use.
Please note that this workaround will not be successful for everyone. If you find the above steps do not work for you, be sure to reach out directly to our support team for further troubleshooting guidance.