Input limiter during capture?

I have a particularly LOUD preamp (it has to be loud, because the output level affects the tone). When I turn down the return level knob, what I’m seeing is that the bar essentially stops moving and stays at a constant dB level. This would imply that there is a limiter or something, or else the meter simply doesn’t reflect the input. I made a video to demonstrate this - in the beginning, I have the amp output set much lower to a reasonable level.

As I increase it, I then go to lower the return evel so as to reduce the clipping. However, once I do that, it seems impossible to drive the return level higher than that amount. Even if I’m blasting ridiculous volume levels into the unit, it stays at that -dB reading. Shouldn’t it be counting to move up and down and clip, even though I’ve lowered the return input level? Is there something weird going on with the A/D conversion when the return input level is very high? It just doesn’t make sense that when I turn it to -12, it’s literally impossible for the level to move above that.

I’d like to know because it will affect the capture process (and possibly pedal inputs and such too). Normally reducing the level would not affect the dynamics - so either it is, or else the meter just isn’t representative. I’ve noticed the same thing will happen if you hit the front end input really hard too.

Here is the video - sorry for the fact that it’s on google: