Azure Functions not running even though the function app says its running

We've identified an issue with our jobs where they seemingly stopped on Sunday without an explanation. The function app said it was running but no jobs were logged, even timer triggered jobs which has been affecting production tenants.

We changed the function app from readonly to read/write and it started back up and has been running since but there's no explanation as to why they've stopped in the first place.

There were no deployments made, and nothing in the activity log other than an Azure Audit that has a successful state.

Can we see why all of the jobs in this function stopped even though the function app itself says it has been running the entire time?

Account info:

Azure region: West US
Function app name: VirtuousJobsProd
Function name: BundleGiftTransactions (timer trigger)
Azure storage account name: virtuousjobsprod
Hub name: JobsHub