Despite a few connection tests that came up good on both my router and my device, my download speeds are in the tens of kilobytes. At first I thought it was my PC, but after trying to download the same file on my laptop, I got the same speed. Problem is, it didn't used to be like this. I've restarted my router multiple times, but I'm afraid that might have messed it up somehow. Any guesses?
Connect your laptop directly to the ONT and retest. This will rule out whether the issue is with the router or the ONT. The ethernet run could also be bad so if testing at the ONT gives good results then test again on the other end of the ethernet.