Welcome to the Community,
how did you update/patch the host to the latest build? Did you use Dell's custom image, or offline bundle (which one), and then apply the latest patches via Update Manager? Do you have any additional drivers installed which may also need to be updated?
In case you have Dell OpenManage Server Administrator (OMSA) installed on the host, please note that ESXi 6.7 U2, and later require at least version 9.3.1.
André
