Surfing Waves

Hey yall, quite a beginner here, recently I've scored this longboard where the shaper says it's completely rolled bottom, fairly flat nose rocker(reverse rocker?), and no concave at all?

But long story short, I took it out on a really small day and it felt like I am struggling to do a smooth clean forehand bottom turn on this board when I hit the flat after pop up & I can't engage the rail/slice the wave proper?

But strangely the backhand cutback seems smoother/clean?

I am goofy so it just feels like the board wants me to surf backhand all the time. I am not sure how to describe this but I don't even have to try to perform a small cutback by consciously engaging the tail/fin, all I have to do is stand up semi straight, hips aligned with board/pointing at the same direction as the board and the board just cutback smoothly on its own?

Is there something I can adjust? or is there a specific way to surf a hull-ish bottom contoured board like this?

Previously I was surfing a single to double concave thinner longboard. Pics for reference if that helps at all...

1) There's a reason why shapers don't make rolled bottom boards anymore.

2) What fin set up did you have on your " thinner longboard " ?

3) Usually beginners SQUAT down too much or stand up too STRAIGHT. I am thinking your posture is straight so giving more power to the HEELS of your foot.

4) Have you talked to the shaper about this particular problem ?