Here's a screenshot of the issue I am having on Windows 10 and Chromebook in both Chrome and Firefox:

That screenshot was taken on March 8th and I am still having the issue as of today. At that time I was trying to reach a real person from phone or chat unsuccessfully, so the screenshot shows they have an circular loop issue with the AI assistant not recognizing this as a type of problem.
Weird. I just tried to see if I have the same error, I didn't. The third pop down menu works, regardless of what I select, and then subsequently the 4th pop down menu.
Screenshot:

Try contacting them on reddit, if it doesn't work like how Bl4nkcode mentioned.
Have you tried contacting their twitter??
https://twitter.com/CoinbaseSupport/with_replieshttps://twitter.com/coinbase?