Ads not blocked from Ubuntu VM after install. Perhaps router configuration?

You should see same results, the block page, as on the VM for all your clients.

In some cases yes.
Some sites publish ads from their own site (dont use 3rd party ad distributor).
Those ads are impossible to block for Pi-hole using just DNS.

From the Netgear screenshot, it seems its lacking particular DHCP server options to get Pi-hole running properly.
It does not allow you to set DNS servers for the clients via its DHCP service.
Best option is to disable the DHCP server on the Netgear box entirely and as replacement, use Pi-hole's DHCP service instead: