Go to the older Lightroom Classic CC folder. It will be almost empty. Open the Modules folder. Copy the Canon plugin.
Open the Lightroom Classic folder. Paste plugin into Modules folder.
Makes sense to me. I'll give it a try. And, I would guess that the next update to Ps 2019 CC will drop the CC from the name and I'll have the same problem with the plug-in. Thanks for your help...