im getting this now and im able to login using a VPN and my phones mobile hotspot.

Ive used  https://www.akamai.com/us/en/clientrep-lookup/

to check and it says did not receive a bad risk score.

ive tried different browsers and computers and clearing caches but still get access denied error.

Ebay are bloody hopeless no help at all esp trying to get you to authenticate when i get access denied responses.