Same problem here. I used the downloaded installer’s Uninstall option to uninstall all versions of my Nik collections in Photoshop 2019 and 2020 and also in Lightroom. Once they were uninstalled, I installed the new versions of Nik in all these applications. Nevertheless, I get two versions of the Selective Tool and only the old one opens even when I try the File>Automate>Selective Tool. Also in the plug-ins folder in Photoshop, both versions, the Nik collections are housed in a Google folder, not a DXO folder. That folder contains all of the collections except Perspective efex. Don’t know where that one was installed. I can access it and all the others in my Filter menu and they work just fine but I can’t get the Selective Tool to appear.