Launcher download speed extremely slow and slowing down

I have a 350mbps connection (tested with both speed testers and other downloads). When I attempt to download a patch, the download speed first spikes to 800kb/s (Not very good for an internet that usually downloads at 40mb/s, but is acceptable, because most of the patches only take 5 or 6 minutes at that speed).
The issue is, soon after, the download speeds start to plummet. They drop about 6-8kb/s every second, meaning that in a minute or two, I end up with 50kb/s and a 2 hour download time. This phenomenon has happened before, but it has never been so serious, as the slowdown rate before was slow enough that I was able to download the patch eventually. Now, its basically impossible for me to download a patch. How can I fix this?

A reinstall seems to have fixed the problem, however, I would still like a workaround in case it happens again. Thank you!

I see this sometimes on all downloads, not just Eve - the fix for me seems to be switching the router off for 30 seconds then on again. YMMV