I have tried two ‘copy post’ plugins. The second one was recommended by GP here:
https://generatepress.com/forums/topic/how-to-duplicate-an-element/
For both of them I’ve found that they don’t correctly copy the color that I have set e.g. for a headline block
I set the color for the headline by picking one of the defined colors e.g. var(–base-3)
After I copy the post and look at the color that the headline has, then it looks like this:
var(u002du002dbase-3)
So the plugin that has copied the post has not copied the — correctly and has converted it to unicode.
It may be the plugins which are at fault and there is nothing you can do in GP, but I just wanted to let you know