Get color cast when switching from healing to content-aware back to healing on single selection

I have Lightroom Classic v12 on a M1 chip macbook air (12.6)

You can now select a previously edited item and switch between clone/healing/content-aware in the heal panel, by clicking on the icons in the panel. This is how I changed from healing to content-aware back to healing.

I selected and edited out the right-hand steel plank with the healing tool (looks good). I made the sparks line up. I then clicked on the content-aware tool (looks OK) for this selected region. Then back to the healing tool with the same selected region, moving the reference area so the sparks line up. All work was done with a single selected editing area. Now the edited area is really teal colored.

The final version takes a really long time to switch before/after with the keystroke \. I think it's still calculating something to do with the AI oriented content-aware, even that isn't needed anymore.

I expected that the first healing to look basically the same as the last healing.