AppleTV + Bose Solo soundbar - remote not "learning"

I have a lg-65UJ6300 (65" 4k) TV

with a Bose Solo soundbar attached via Optical to the TV.

The Solo has a small standard IR remote.

I have the "Simplink HDMI-CEC" setting turned ON on the TV.

I recently purchased an Apple TV 4k edition, and obviously want to use the Apple TV remote to control the Bose soundbar.

However, the Apple TV refuses to Learn the IR signal from the Bose.

It DOES register the IR signal from the LG remote in learning mode (but that's useless, since I don't use that remote to control any volume.)

I had previously used Tivo, and the was able to get the Tivo remote to learn the Bose signal.

But this Apple remote will not. It refuses to see the + or - signal during the learning process.

I'm not sure who's problem it is ... something in the Apple TV?

Is there another setting on the TV that might be preventing this???

It's all brand new gear that should easily work together. I'm really stumped.