Why submission 286655 and 286848 hang?

After the debug generation end, the status still shows validating submission

url: AIcrowd | Single-source Augmentation | Submissions #286848

this submission also hang: AIcrowd | Single-source Augmentation | Submissions #286655

this submission has graded, but it still show submitted: AIcrowd | Single-source Augmentation | Submissions #286885