I would say it's because of bots and people are probably using Chrome or other Chrome variants or Chrome user agents to do fraud. Plus, they probably have got some hits from your residential I.P range with hacked accounts. Unless you are using a vpn? But big e-commerce sites like Amazon & eBay have other ways to block malicious traffic and don't usually block you just because you're using a vpn, sometimes you get captchas, but they still let you buy even with vpn which is strange