The issue is probably with the game servers you're connected too. If you're getting good speeds with the store and steamlink apps, your connection is OK and the speed is OK on your side. It could be an issue with your internet provider, sometimes they throttle particular downloads for some unknown reason. I had the issue myself. I have a 1 GB speed and had the same barely moving downloads on some games. I changed my provider a few months ago and it hasn't happened since then. Not saying it's definitely the same for you, but you never know. Also, maybe it's a temporary thing with your provider. Just in case try restarting your modem anyways. Good luck, I know it's very annoying hanging around for something to download properly.
