If this is paywalled behind a Viewport license, which i own v3 of, having just upgraded to PL7, I’m seriously done using DxO products.
This is aggressively anti-photographer.
Insane.
According to DxO’s compatibility chart VP3 is compatible with PL7. Have you activated it yet?
The 'flip image option is part of ViewPoint 4, i.e. to get at the flip option you do need to upgrade VP3 to VP4…
I didn’t upgrade VP3 to 4 because for me it’s not value for money since I can use Affinity Photo if I ever need to flip an image.