next-gen status is partially although next-gen is created for all thumbnails when enable avif

Before submitting an issue please check that you’ve completed the following steps:

• Made sure you’re on the latest version => 2.2.0.1
• Used the search feature to ensure that the bug hasn’t been reported before

Describe the bug
When enable avif, while medium image is optimized, next-gen status is partially although next-gen created for all thumbnails

To Reproduce
Steps to reproduce the behavior:

1. activate imagify
2. upload attached image
3. check media library => next-gen generated is yes
4. enable avif and wait till avif is created
5. check media library (refresh the page) => next-gen generated is partially

Expected behavior
next-gen generated is yes as long as all image thumbnail have next-gen
Screenshots
If applicable, add screenshots to help explain your problem.
test image

Additional context
Add any other context about the problem here.

• if same image was uploaded while avif is enabled , the status of next-gen generated will be yes so the problem is when image is uploaded before activating avif

Acceptance Criteria (for WP Media team use only)
Clear instructions for developers, to be added before the grooming

Reproduce the issue in the Media Library using an image uploaded before AVIF was enabled, following the listed steps. Compare the next-gen status before and after AVIF generation; the work is done when it reports yes whenever AVIF exists for all thumbnails, including previously uploaded images.