Too much Network usage
Teams takes up too much network usage on startup (I think when navigating to a chat with many GIFs).
It may not be noticeable on a network with unlimited fast internet, but on a network with 4mb down and 2mb up, it is. I saw in task manager Microsoft Teams is using 2-3mb of the network. This stays like this for quite a while.
Matthew Steeples commented
Hi James. Are you sure it wasn't downloading an update at the time? We rarely see Teams take any bandwidth unless we're in a call.