What's the lowest altitude you can fly at (at say 400m distance) without losing signal?

[MarkTun]

This DJI mini 3 Pro is my first drone and I'm trying to figure out if its behaving normally or not

If I fly at 20-30m altitude, about 300-400m away, I lose almost all my signal or most times even disconnect entirely

Is the signal being this weak normal?

What's the lowest altitude you can fly at (at say 400m distance) without losing signal?

As others have already pointed out, it's likely not about your altitude, it's about whether you have obstructions, trees, or other things that impact your signal.

Since your question is essentially one of range, for what it's worth, I did range testing last week on an unobstructed beach mostly over water, in a couple different directions, at a height of 100 feet and distance of 5000+ ft. Never lost a bar of signal. Will do more over populated areas once I get a nice clear day.