Hello Jeromy
After doing some research, I have found that this seems to be a bug that appears occasionally. Some bug reports do indeed suggest the fix you mentioned, while others state that it has to do with a manually configured ip routing command on the vEdge. These involve releases 17.3.1 20.3 20.3.1 20.4 20.4.1, and cEdge-16.10.1 respectively. Rene used version 19.3.0 in his lessons.
The only thing I can suggest is to see if you can obtain the same version as Rene to duplicate his implementation. Otherwise, you can troubleshoot using Cisco TAC (if this is a production network) or other workarounds posted online.
Let us know how your troubleshooting comes along!
I hope this has been helpful!
Laz