Recently, the TF2 servers were undergoing a series of performance issues, this has since been solved.
I wrote up a break down of what was happening, why, and the solution as a free post on our Patreon!
https://www.patreon.com/posts/scg-rubber-band-147187212
Please feel free to read if you're interested! The TL;DR is that the problem has been fixed, and we are moving all hosted servers to new hardware. You do not need to adjust your favorites, and the full details of this move will be posted soon. Thank you for your time!