Hello everyone,
I got the replacement of the air unit from my reseller, and the Cubepilot team helped in making it quick.
The new air unit is working fine without any disconnections, with the same connections as the previous air unit.
Hence I can conclude that the previous air unit had some fault which was causing it to “reset the link” as @Michael_Oborne confirmed from the logs.
Thanks everyone for your support, especially @philip and @Michael_Oborne