Two possible reasons why this is happening:
1. All Canvas ZOOM Cloud recordings are now private by default in Canvas.
2. All new ZOOM Cloud recordings are now password protected.

Publish your Canvas ZOOM recordings

All Canvas ZOOM recordings are private by default. The meeting host (course instructor) will need to go to their Canvas course -> ZOOM -> Cloud Recordings -> Click the Publish toggle.

Once the recording is published:


The password will automatically copy to the computers clipboard when you press play. You can then paste it into the password prompt that opens in a new window.

Students will be able to use these options to copy and paste the password when prompted, and then view the recording.

On each recording you have two options, 1 allows you to view the password, and 2 allows you to copy the password.

NOTE: Once you publish a Canvas ZOOM recording, your students can access the video by going to Canvas -> ZOOM -> Cloud Recordings -> click the record title to view the video.

ZOOM Recording Password

March 14, 2020 ZOOM Security Update – Cloud recordings:
Password protection for shared cloud recordings is now on by default for all accounts. We’ve also enhanced the complexity of passwords on your cloud recordings. Existing shared recordings are not affected.

Source:
ZOOM updated their security on cloud recordings this week.
https://support.zoom.us/hc/en-us/articles/204758419-New-Updates-for-Web

Problem:
Instructors are reporting that their students can not access their ZOOM cloud recordings.

Solution:
Go to http://udenver.zoom.us -> Click Log in -> Click Recordings -> locate your webinar recording -> click Share, you should see the cloud recording password -> click the Password Protect toggle.