I have residential fiber from a local isp @100mbps up & down, and have definitely noticed netflix has been horrible for a few weeks (appletv).

I took a look at my airport stats, and it seems the atv had connected at 1mbps to the AP, which would certainly cause problems. A reboot of the ap & the atv resolved the issue.

If you have apple gear, you can see the data rate for your device by option-clicking the AP in airport assistant.