Issue Summary

This is reproducible on Data Center: (yes)

Adding a Slack link as an attachment to a card requires the Slack Power-Up to be enabled. We can click the 'Hide this section' button, and the attachment will go under the Attachments section. However, once we refresh the page, it comes back as a Slack preview.

Steps to Reproduce

Loom - https://www.loom.com/share/183d6af1843d4f60b2e3ef693562b63e 

Expected Results

Save user's preferences on how Slack attachments are displayed on cards.

Actual Results

The user's preferences are not being saved for those attachments.

Workaround

Currently, there is no known workaround for this behavior. A workaround will be added here when available.