This issue is happening in my company to half our office (over 300 users). Some have downloaded recent updates others have not but are all experiencing the same problem. I would like to say to admins here if we are on this thread 100% sure people have tried all the options listed through out without getting a solution hence further comments and critiques.
I believe the bigger issue is that this feature is controlled by 1 person who has control over the entire Teams for a company and should be moved to a user level not admin level. Let the individual users chose to turn this feature on or off ,not have it for one person to control everyone's abilities. This isn't the Lord of the GIFs, we don't need 1 admin to control them all.
This is one of the better features allowing users to communicate with feelings and suck's to no longer be able to make co-workers laugh and enjoy their day through humor and well wishes.
#GiveourGIFsBack