By your screenshot it looks like the DVswitch is set to no failback but your port groups are still set to True,
The port groups could be overridding the inhertance from the DV Switch, if this is the case you will need to change it on your port groups as well.
No. That's what is confusing me. As described, it is actually the opposite. All the portgroups have already been set to "No" but the PowerCLI command shows "True". Also, I blocked out some of the port group names but what you are referring to as DVswitch is the "DVUplinks object under the dvSwitch which can't be modified. It is set to "Yes" but PowerCLI displays it as "False" (see images).
I was hoping someone could validate this behavior or better yet confirm that my portgroups are truly set to failback depite what I'm seeing in PowerCLI.