@fernleyfarm 

Several things to check.

Are you using a VPN?

What are DNS settings as that can block sites. 

Clear your browser history.

Try a different browser. 

Check the security settings. 

  @ArcherC8 

I don't know what most of what you asked are. The only thing I ever changed was the network name and password. My desktop is wired, my laptop is wifi and my phone is wifi. I did a factory reset for the roter and it made no difference. The desktop, laptop, and phone only connect to eBay if the router is bypassed. I have had all of them for several years including the router and never had a problem til today. The desktop uses chrome. I tried FireFox but the same thing happens. The laptop is a mac running Safari. The phone uses Google. The router is the coimmon thread.

  @fernleyfarm 

Try changing the MAC of the router to use 'select use PC MAC' which should be in the advance internet settings for most routers. Be sure to power cycle both the modem snd the router.

Another thing to try is change the use of IPv6. 
 

If these do not work, post the router model and version so we can see the options available for that model.
 

  @ArcherC8 

Thanks,

I didn't do a thing and it started connecting fine. Ebay insisted the problem was at my end. Said the problem was with my local server. I don't know what it was but it works now. Maybe the problem was with Spectrum.