Web App for Containers - Linux Ver - Disappearing VNET Integration Option

Issue: When configuring VNET integration on a Web App for Containers, Linux version, and selecting a given subnet, the VNET ingration screen disappears from the networking blade. Sometimes it takes a few minutes for it to disappear, sometimes not. Also. there seems to be no error handler when multiple apps are configured to use the same delegated subnet, which the documentation says should be a one-to-one relationship.