X15 remote powers on TV or soundbar, not both

My X15 remote will either power on my TCL Tv or my Vizio soundbar, but never both at the same time. I went through all of the pairing steps, but whichever device I pair last is the one that works with the remote. I know there have been other posts about this, but none of the proposed solutions have worked for me. I have tried resetting the remote. Am I missing something? Does the soundbar have to be connected to the tv using hdmi arc for this to work?