P: Spot removal removing brush stroke

Further more extensive tests on my Windows machine. Tests on DNG, JPG and RAF also including some performance impacts. Here are the details, I'll let you draw your own conclusions except for 3 of my observations: 

1. Auto Mask is a performance hit
2. Results are dependent on the image and number of modifications
3. No issue with jpegs

New tests on a DNG:
 
1. GPU off, Mask on or off, the problem doesn't occur.  

2A. GPU on and Auto Mask on, for this photo, it is necessary to remove at least 3 spots before the brush is partially undone. Prior tests with this photo have caused the partial removal of brush strokes with only 1 spot removal. 
  
2B. Same as test 2A except Auto Mask is off. The problem doesn't occur until at least 4 spots are removed.  

3. Problem exists in the Develop module, returning to Library and the photo display correctly. Returning to develop and the problem returns. 

New tests on a JPG:
 
1. All tests show no problem. 
 
New tests on a RAF (Fuji raw): 
 
1. GPU off, Mask on or off, the problem doesn't occur. 
 
2A. GPU on and Auto Mask on, for this photo, it is necessary to remove at least 8 spots before the brush is partially undone.  

2B. Same as test 2A except Auto Mask is off. The problem doesn't occur even after 51 spots were removed. 
 
3. Problem still exists in Library module. The defect is exported. 

Note 1: Auto Mask slows down painting. 
 
Note 2: Auto Mask slows down spot removal by at least a factor of 4, probably more. 
 
Note 3: my hardware configuration 
 
HP Z440 
Xeon E5-1650 V4 6-core 3.6/4.0 GHz
64GB ECC RAM
Windows 10 Pro 64-bit 
Nvidia Quadro P2200 5GB (default scaling) 
Dell 27" 4K P2715Q 
Benq 32" 4K PD3200Q 
Samsung 950 Pro 512GB - C-drive
Samsung 860 EVO 2TB 
   -dedicated to Lightroom 
   -Samsung Rapid Mode active 
   -on a PCI-E adapter 

This happen on my Mac 10.15.7 also. A few observations below

1. It seem to happen on most images but sometimes the change is VERY subtile. 

2. Switching to Library clears the issue.  

3. Exported file doesn't have the issue.

4. Happens on JPG and Raw files (didn't try a Tiff)

You can upload to any storage like dropbox or others and share the link over here. 

If that does not work for you, please let me know.

Regards,

Ganesh

Erm. Sorry. New here. How best to do that? I can't upload directly here. 

@bill_3305731 @i4detail @Derek Richbell 

Please share a sample image along with develop settings (xmp file) where the issue is reproducible. Or export the image with settings to a fresh catalog and share with us. 

Regards,

Ganesh

Good to know. I can breath a sigh of relief for the moment.

@anthony_blackett 

Oooh. Good call. You're right. It does display properly in the library. But, when I go back to develop, it's back to showing the wrong effect. Hang on...

If I export the image, it shows the original edits. 

If I shut down lightroom and re-open it, it displays correctly in the develop module. 

So it appears to be a display issue, not an actual changing of the mask issue. Good to know. Basically until there's a GPU hack/fix, treat it like Mysterio and don't believe what you see in the Develop module. 

Which is not the best situation to be in, but it is better than having to re-do the masks after the fact....

@181561_3305731,  I still cannot reproduce this bug, even following your steps.

Is this really removing the brush strokes or is it a GPU rendering issue? What happens when you return to the Library? Are the brush strokes still missing? I say this because my PC is too old to use the GPU for image processing - my GPU can only be used for display.

Rikk, 

There are multiple unrelated posts in this thread which is why I started a separate one for just this problem. 

Bill 

@bill_3305731  Please keep all related posts together. It is harder for our teams to go searching for orphaned posts.  This post is authoritative and links directly to the Bug reporting system.