A couple of years ago there was a problem with tivo remotes where no learning remote could be taught the FF command of them, the only remedy was to get the command from a different source, either another remote or use the preset commands. You might have similar problem here with thumbs down command.

Have you used both tivo peanut remotes to teach? They might be from different batches, just change it to the address two and try it.

The one-for-all universal remotes like the urc-6820, 8820, and 10820 have preset codes for tivo remote addresses 1-4. Each has access to advanced codes, so if the thumbs commands aren't preset, then can be mappedvia advanced codes. which are 5 digit codes for individual functions. Then you can use them to teach the urc200, the urc6820 & 8820 can be had For under $20 on-line.