This has happened to me a couple of times in the past and both times it was solved by redownloading / updating the Azure Functions Core Tools and then try again.

https://learn.microsoft.com/en-us/azure/azure-functions/functions-run-local?tabs=macos%2Cisolated-process%2Cnode-v4%2Cpython-v2%2Chttp-trigger%2Ccontainer-apps&pivots=programming-language-csharp#install-the-azure-functions-core-tools