This leads me to believe this to be more of a system wide resource constraint causing this missed communication.
Having a further look at the system logs for this system confirms this as LLT, which is a complete separate protocol running in the kernel space had resource constraints around this time period as well :
You can see these messages below interspersed with the VCS agent messages.
It looks like the resource constraint lifted, if it would have continued much longer it would have also resulted in a node panic.