I have attempted 10 captchas in a row, but to no avail. Each time, the response is marked as incorrect. The login issue is only part of the problem. When I try to redeem a freebie on my account, I encounter the same captcha issue. This persists regardless of whether I am using a VPN or not. It's becoming extremely frustrating.
Is it one of those click all pictures that contains a buss/bicycle ones. Because I have noticed that some of them after you have clicked all the relevant pictures will give you more pictures to click but there sometimes is a significant wait before the pictures refresh into the new ones, with no indication that there will be more pictures and if you press compleat before the new pictures load it will fail you.
What browser are you using? Some browser features have caused issues like this for me in the past. Specifically privacy-focused browsers like LibreWolf and Vanadium.