Youtube controls (managed from the youtube tab in each custom policy) can interact with different filtering methods in different ways. If you are struggling with videos being blocked when it seems they should be open, please review the following behaviors:

Youtube + Chromebooks:

In accordance with the screenshot below, if your school is only using chromebooks the easiest method for smooth and simple youtube controls will be to rely on Google Admin (GSuite) YouTube settings. Having Teachers with “Can approve” permissions, and Students with “Moderate or Strict” restriction modes is typical for most schools. Teachers can then just approve video themselves without asking your tech team to add the video to the allow list of your Student policy in the YT Tab of Securly.

NOTE: If this setting is OFF under YouTube App controls in GSuite, then filtering of YT content might behave differently based on the filtering method used:

DNS and Smart PAC filter --> all youtube restrictions will be controlled from Securly YT Tab, GSuite youtube restrictions are ignored.
Extension: Restrictions continue to apply regardless of Securly or GSuite YT app settings. So GSuite will take control.

Youtube + Other devices:

In accordance with the screenshot below please keep in mind that other non-chromebook devices may not have all available features, as some are extension only. For devices you choose to use securly youtube controls keep this in mind, as it may impact your overall strategy!

Access restriction modes - These will match the above google-created restriction modes in unrestricted, moderate, and strict.
Channels - If you are receiving an error when trying to put in a channel, you may need to switch from the vanity URL to the Youtube ID URL. Please reference this guide for more information!
Videos - Allows plaintext youtube videos, and works on all filtering methods.
Categories - Uses the user-defined and google-curated tags placed on youtube videos to help filter videos out. These tags cannot be edited in GSuite, nor by Securly.

Youtube Controls - User guide & Best practices