When Edge is configured as dual stack [both ipv4 and ipv6] and the IPv4 address has an empty Gateway setting then the IPv4 mgd communication will fail if the corresponding IPv4 interface goes down. This will cause the edge to go offline on the orchestrator.
This issue can occur if the Edge was activated with only with an IPv4 link, with an IPv6 link added only later. At the time the Edge is activated, only the IPv4 Orchestrator address is written to the Edge "management IP address" that manages Orchestrator connectivity. Adding an IPv6 link later does not add the IPv6 address to the "management IP address". So if the IPv4 link is removed and IPv4 link doesn't have the default Gateway address, the Edge loses connectivity to the Orchestrator.
The best solution is that uses FQDN in Operator Profile and DNS server is able to resolve the FQDN by providing both IPv4 and IPv6 addresses.
If customer is having on-prem setup and does not have the FQDN for the VCO then this issue has two workarounds: