Why does Siri respond differently on my TV and Apple Watch?

I configured my tv into Apple Home years ago and had been talking to the HomePod to turn the tv on/off.

About a year ago, something broke and the command to turn the tv on might work once in 30+ attempts. But, the command to turn the tv off has always continued to work fine. (Removing & adding the tv back into Apple Home did not fix the issue.)

However, making the same commands (both on &/or off) into my Apple Watch has always worked 100% of the time.

Why?

Can this be fixed?

[Re-Titled by Moderator]