stamp tool will not change pixels in region of layer that was part of previously crop-gel-expanded

MacOS 18.1 , Photoshop Classic 26.0.0 11/16/24

Using stamp tool on a layer that filled the canvas, as pixels changed, the pixel area that was the result of a generative-expand-crop function previously, would not change. The stamp tool would not work on this region of pixels.

Previously, I had expanded the cropped region to a larger area using the crop-generative-expand. Throughout my edit session, I would periodically merge visible layers. I was down to a single visible layer and was using stamp tool when the region of pixels uniquely in the epand area were not affected by the stamp tool. I checked to confirm that those pixels were not part of another layer that, while marked invisible, was somehow visible.

The reason I had been merging layers together, sacrificing some control of the image, was because I was having a lot of trouble with generative fills when multiple layers affected the content. Often, I would get "service not available" or long (30 sec-2 mins) to get results. 

The canvas was 24"wx12"h @300ppi

This was my first use of the gen-fill features. 

I should point out that there were lots of other bugs in this session. One time all the layers, without keystroke, reduced themselves to 2 layers that were very small (2"x1")regions of zoomed-in content. I had to reopen the doc.

Model Name: iMac

  Model Identifier: iMac20,1

  Processor Name: 8-Core Intel Core i7

  Processor Speed: 3.8 GHz

  Number of Processors: 1

  Total Number of Cores: 8

  L2 Cache (per Core): 256 KB

  L3 Cache: 16 MB

  Hyper-Threading Technology: Enabled

  Memory: 16 GB

  System Firmware Version: 2069.40.2.0.0 (iBridge: 22.16.11072.0.0,0)