Image problem - image has a "GRID" on it.

I have a problem, and it’s one I’ve never experienced before. When I exported this image from Capture One Pro it was fine, but when it opens in PS it has a “grid” or “texture” on it. I have no idea why this grid has appeared.
 
Full workflow from camera to here:
Shot with a Nikon D810 - 1/125 sec @ f/16 (iso - 3200) No filters, handheld from boat
First processed through Pure Raw 2 because the ISO was so high
Processed through Capture One Pro (latest version, just downloaded latest update last week) Other pics have had no issues since the update. No grid pattern on image in Capture One.
Exported to PS as: TIF - 16 bit @ 360ppi, uncompressed, Adobe 1998 profile, no output sharpening (I’ve also gone back and exported as PSD, PNG, & JPG and the grid is on all of them)
 
Has anyone run into this issue before? Any ideas?

Two images below:  One small clip @ 100%; one of full image @ 2000 pixels wide

[font=Lato, sans-serif] [/font]
[font=Lato, sans-serif] [/font]

archfotos wrote: Very interested to hear your thoughts and if you nail down the problem.

Thanks, that's interesting.  I've had a similar suggestion elsewhere, suggesting that I forego running through Pure Raw 2 first, which corrects lens distortion and also corrects noise.  I'm fixing to experiment with that this morning to see what effect that may have.  I actually hope that's NOT the cause because this image really benefited for the run through Pure Raw 2 due to being handheld and high ISO.

Will post my results.

OK, I discovered the problem, but I can't figure out why it happened. The problem had nothing to do with running it through Pure Raw 2 first, thankfully.

I went back in Capture One, into Layers, and turned off all the layers and exported it, everything ok. I then went through and turned on 1 layer, and went through all layers just exporting one layer at a time and discovered the issue. In Capture One, I made two HEAL layers, one for water & one for the trees. For whatever reason, when the second HEAL layer was turned on, the grid appears. None of the other layers caused any problem. I have no idea WHY the second HEAL layer caused it but I will be going over that layer with a fine tooth comb to see if I hit something I shouldn't have or didn't hit something I should have, but I'm very happy I discovered the issue and I don't have to go back and start over from scratch with the processing.

Thanks for your suggestions and help!

Wow, please be sure to report this to Capture One as it appears to be a bug.