Issue with Heartbeats in 2 out of 6 end points

I’m having an issue with failed heartbeats in two components out of 6. Both are APIs.

It doesn’t seem to be causing any problems and I’ve asked out environment team to look into it, but i thought i’d ask here in case you’ve seen something similar.

The failures coincide with with a cryptography error we see almost every 15 hours. I though it might be IIS recycling but that’s configured with the default 29 hours.

The cryptography errors have been occurring since we went live (last October) but the failed heartbeats only seems to start last month, possible after we upgraded NServiceBus.

ServicePulse: 1.25.4
ServiceControl: 4.12.0
NServiceBus: 7.4.6

Is it possible that, since they are both API endpoints, that NServiceBus is being lazy-initialized the first time an API controller needs to call a messaging operation? If that were the case, while the API endpoint would be “up”, the NServiceBus endpoint (I’m guessing a send-only endpoint) would effectively be “down” as far as heartbeats were concerned, until the first request initializes the NServiceBus endpoint and heartbeats resume.