P400 Optimizer dropping out ? - is this normal ? P_OK = 027/028 intermittently

[JRqwertyui]

Need help diagnosing an intermittent issue:

I have 28 330W Panels divided between east and west facing. During daylight hours 8am-4pm'ish all is P_OK = 28.
But then, intermittently, I see P_OK = 027/028. I assume that one panel/OP is dropping off. Is this normal when dusk arrives ?

I was attempting to look at solar edge monitoring and found this ?

IMG_8261.jpg

am i on the right track, or is this common or caused by shading ? is this indicative of an OP/Panel going bad ?

[JRqwertyui]

The other panels facing west also decrease quickly, but don't stop reporting...

IMG_8260.jpg

[JRqwertyui]

Module 11 stopped reporting between 16:52 and 18.16... How often should modules report in ?

module11.jpg

[Mike 134]

My "expertise" is limited to what I am familiar with. How do each of the panel's outputs compare when you look at a month's production?

[JRqwertyui]

Mike 134 thank you for your reply...
Panel 11 and 28 (very bottom center) are underperforming - but hard to tell if this is due to shading...

File (3).jpg