I do make the trade, but after the message from Duking to take care of his Croconaw, the game freezes. Duking, the player character, and the old woman do not make any motions at all, and the music goes on for a second or two before looping back. That was for the Dratini trade for the Croconaw, and the same happened with the Chansey trade for the Quilava. I haven't found an Aerodactyl yet, so I can't test that trade for the Bayleaf, but that's what happened for me with the trades I attempted.
The trade of the purified Togepi for the Bonsly worked fine, however. My version of the game is 1.0.7-2, which might not be the most recent update, however. I probably should have double checked if there was a new update first. Whoops!
Edit: I updated to the latest patch, and it works just fine. Sorry about the false alarm! I'll be sure to keep better tabs on future updates from now on!