This is a brand new installation of a Wireless Wire Cube Pro, that came with RouterOS 6.49.15.
I upgraded the “far” end of the link to the latest version of RouterOS 7 and rebooted, and the device dropped off the network and is no longer responding. The “near” end is still on 6.49.15.
Is this a case of both ends needing to be on version 7 to communicate?