Volume when using Apple TV 4k is significantly lower than using apps built into my 2022 Samsung TV
When using the Apple TV I have to turn up the volume as high as 75 vs 20 when only using the Samsung apps.
Has anyone found a solution to this?
Low volume out of the ATV4K, relative to other devices, is not a known problem.
I've only seen something like that when sending audio to the ATV4K via AirPlay from my Mac or a stereo pair of HomePod minis in an adjacent room. In this "whole home" case, the AirPlay volume control for the ATV4K (see image) is more of a "line-level output" setting from the sending device - it DOES NOT actually turn the volume knob on home theater receiver in the other room (and you really wouldn't want it to). You could look at the AirPlay volume sliders as a percentage of the remote device's current volume setting.
You get this same effect when your iPhone connects to your car stereo via Bluetooth, and you crank the car's volume to the max before you remember to turn up the volume on the dern iPhone and blow your ears out :-).
If this isn't the scenario you're talking about, you'll need to give us the details about your system components and each one's settings.