There's not much detail here, but I'll take a wild guess that you might be trying to control a Roku Stick model with a simple (IR) remote. (Stick models need RF/Wi-Fi remotes - voice remotes.)
But I suppose another guess would be that when you say 3 other TVs, that this is a Roku TV remote and the non-working device is a Roku player.
Correct - it is an old stick and the replacement remote does not work on the Tv - I have other TVs in the house that are either Roku TVs or have a stick and the same remote does work with each of them.
I replaced the existing Stick remote with the same type new remote and it’s not working
There basically are three types of remotes from Roku:
Roku Voice Remote (several models) - Controls via WiFi direct to the Roku. Has limited TV control buttons. By default. TV Power, Volume, and Mute controls use infrared (IR) to control the TV, but can be set up to support TVs that support these controls over the HDMI connection (CEC). Works with all current Roku streamers and Roku TVs, and all but a few very old and obsolete Roku models.
Roku Players Remote (formerly called the "Simple" remote) - controls Roku players via Infrared (IR). Controls Roku functions only, has no TV function controls. Direct line of sight needed to IR receptors on any visible Rokus. IR remotes are not paired, they just work with any IR-equipped Roku. Similar remotes from third parties are available on sites like Amazon and eBay.
Does not work with:
Roku TV Remote - Controls via direct line of sight infrared (IR). Works with Roku TVs from all manufacturers. IR remotes supplied with non-Roku branded TVs are from the TV manufacturer, not Roku.
Does not work with: