Additional chat-related features and issues within Microsoft Teams for business
Hi Sarah,
From what I can see, GIFs are sending but you aren't able to see them. Therefore, it's likely that your system administrator is blocking Giphy, which is the platform used to share GIFs within Teams. You'll have to contact someone within your organisation's IT department informing them about this and see if they can provide further information to verify if this is the case.
One more suggestion I'd try is to access the Giphy site and see if GIFs load there, although even if they load, it might not be a conclusive sign that Giphy isn't blocked specifically on Teams: https://giphy.com/
Kind regards, nt1809
Note: if any of my responses have been of any use to you, I would greatly appreciate it if you could mark my response as helpful as your feedback would greatly benefit me in improving as an independent advisor, thank you!