I have 2 ROKU tvs and both remote to TV signaling are terrible. I thought the first one was because it was up high in my kitchen. The other is not and have to stretch the arm up to change the channel, volume etc. And yes, batteries were changed.
Buy wifi voice remotes for each, the signals go through walls.
Over the decades I have had many IR devices and they all have somewhat different IR patterns. Some manuals are nice enough to document this: for example, one allowed 45 degrees off-axis horizontally, but only 10 degrees vertically. I’m guessing they do stuff like that to reduce interference from overhead lights. On the high-up one you might try angling it more downward. This might improve the picture too as a lot of LCDs have inaccurate color off-axis. Of course, like @Tivoburkee said, it’s great to have the Wi-Fi remote option too!