Didn't see that part but that's not why it's not working, to fix it:
Stop the array, stop Docker/VM services, unassign all cache devices, start array to make Unraid "forget" current cache config, stop array, reassign all cache devices (there can't be an "All existing data on this device will be OVERWRITTEN when array is Started" warning for any cache device), re-enable Docker/VMs services, start array.