Quarantine - Certain Users Not Showing

We have our environment setup to where we get active alerts for any emails that are requested to be released from quarantine. My team then goes in and looks at the email to make sure it is legit enough to be released.

Since we have been doing this, we have noticed that certain users will not show up in the quarantine section from time to time. Even though I can pull up the email in Explorer and verify that it was sent to quarantine, it cannot be searched or found in there. I was even able to verify several OTHER users who received these quarantined emails and they do show up.

I thought at one point it was just certain emails but recently verified that it is the user themselves. Even though I can verify that 100+ emails have been received and sent to quarantine in the past 30 days by a user, NONE of them show up in the actual quarantine section of Microsoft 365 Defender no matter how it is searched for.

Does anyone have any possible fixes for this? It is very frustrating if we are trying to manage these emails for our end users.