Website Blocking

When on the comcast network, my company website www.arcalea.com is inaccessible, however on celluar it is fine. Do I need to request a whitelist?? Thanks in advance!

Also just tried to access via Opera VPN browser and was successful, so it does appear Comcast is blocking. Is Comcast blocking for ALL potential customers of our company?!!? How long has this happened? We need this reversed ASAP - please help! Thanks @ComcastJosh or anyone else!