Remote control signals are indeed just an IR light being turned on and off, but there is also a carrier frequency to consider. While most remote signals use a carrier frequency between 38kHz and 40kHz, some use frequencies much higher which are difficult for learning remotes to capture.

However, in this case, your "fishy" suspicion is most likely correct.

In all likelyhood, the correct code for a "One For All" remote for your TV is TV/0463. This code uses the NEC2 protocol, which is probably the single most common IR protocol around, so if a learning remote cannot capture this signal, it's not a learning remote!