I have a similar problem to this one, only I'm using tikz-cd instead of tikz.
Here is a minimal example:
\begin{frame}
\begin{tikzcd}[ampersand replacement=\&]
1{\uncover<2->{\arrow{r}}}\&2
\end{tikzcd}
\end{frame}
This will have two slides, both having the arrow. Removing the {...} will lead to an Error:
Giving up on this path. Did you forget a semicolon?
Using \only instead of \uncover does work, but does move things in bigger diagrams, which I don't want.
Is there a workaround without converting all my tikz-cd diagrams into tikzpictures?

|[key=value]|before the node. Thus, node 3 can be shown from slide three onwards with|[visible on=<3->]| 3. – Tom Verhoeff Jul 28 '19 at 12:01