Magical cure for lower back fatigue: Rowing exercises

I experience no pain or discomfort doing squats or deadlift and progressing well. However when I am not working out, throughout the day my lower back gets fatigued and tight while standing. Within few seconds. I have to sit repeatedly to “normalize” it. It almost “felt” like some imbalance or something misalignment, something like that. I tried doing barbell rows few days back and that seemed to help. Yesterday I tried rowing for 15 mins on a Concept 2 rower. And it was almost magical impact. The back tightness and fatigue almost disappeared completely. Lets see how things goes over next few days.
I have read Dr Baraki’s articles on pain but this experience seems to defy anything that I was expecting. Is it a sign of certain parts of my musculature becoming more stronger than others?

No, it’s not a sign of anything in particular.

Movement is good, in general.

Ok thanks!

Everyone’s different department: My back gets tighter when sitting unless I’m sitting very upright. Standing makes it feel better. Stretching (yoga poses or otherwise) also makes it feel better. Movement is good.

Often, moving around makes people feel better.