Frog skin Acro - Losing Color?

[PotatoPig]

I did a top-down view of one of my acros and noticed some of it has paled a bit, and on closer inspection it looks like this side (which has previously grown the fastest) has fewer polyps extended - see photos below.

This side is also the one with the fastest flow, don’t know if that’s connected but I’d have thought it would be the other way around if one side was going to have issues.

Is this anything to panic about, or normal, or just wait and see?

Calcium: 400
Alk: 8-9
Mag: 1400
pH: 8
Salinity 35
Temp 78
PAR here: Approx 250. I recently turned the lights up about 2%, so if it’s reacting to light the light has recently gotten very slightly higher PAR.

 

[KrisReef]

I don't see any obvious issues in these photos. Stuff that starts growing often grows in the opposite direction than we expect, and color changes along the way are also common as a coral starts doing its thing.

 

[PotatoPig]

A few days on update - good PE on one side, but little or no PE on the side that’s going a bit pale: