We have verified the failing requests on Healthchecks.io dashboard were indeed related to object storage availability issues. The temporary solution of disabling "get object" API calls has restored the dashboard functionality. Our object storage provider has acknowledged the issue and is working on it.
Currently on Healthchecks.io dashboard, when you view details of a recent ping you will see a "The request body data is not yet available, please check back later." message. The request bodies are not lost, and will be available for viewing eventually.