[Bug]: Soft Inpainting doesn't do anything: Automatic1111 Outperforms, Possible Forge Issue

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### Checklist

- [X] The issue exists after disabling all extensions
- [X] The issue exists on a clean installation of webui
- [X] The issue is caused by an extension, but I believe it is caused by a bug in the webui
- [X] The issue exists in the current version of the webui
- [X] The issue has not been reported before recently
- [ ] The issue has been reported before but has not been fixed yet

### What happened?

I recently came to an understanding while following a tutorial on inpainting that featured the "Soft Inpainting" option. Despite adhering to the instructions and utilizing the "Soft Inpainting" checkbox within Forge, it didn't perform as expected—especially when I increased the mask blur, which what was demonstrated in the video using the latest Automatic1111 fork. The inpainting results from Forge tended to be more blurred overall. In contrast, I've found that Automatic1111 provides much better outcomes, although Forge operates significantly faster and without VRAM errors. I would be immensely appreciative if this issue could be addressed. I applied the same "Soft Inpainting" settings on both platforms.


### Steps to reproduce the problem


### What should have happened?

When enabling "Soft Inpainting" it should preserve the masked selection and inpainting.

### What browsers do you use to access the UI ?

Google Chrome

### Sysinfo

[sysinfo-2024-03-05-10-43.json](https://github.com/lllyasviel/stable-diffusion-webui-forge/files/14494031/sysinfo-2024-03-05-10-43.json)

### Console logs

```Shell
None
```

### Additional information

_No response_

Start by reproducing the report with the same Soft Inpainting and mask-blur settings in Forge and Automatic1111, using the attached screenshots and sysinfo as reference. Compare the resulting masked regions and identify the relevant inpainting path; the issue is done when Forge preserves the masked selection and produces comparable results.

Written by the indexing model from the issue text.