I recently signed up for VPN and have it installed on my computer. I don't know it's got anything to do with it.
Also, on the bottom of the page there is an option to report the issue so report the issue. You can also contact (call or chat) the help center, https://www.chegg.com/contactus/#/path/Chegg-Study/ during office hours.
I am attaching screenshots of the same for Chrome browser. You can follow the same steps for the browser you are using.
I do not know the browser that you are using or other details like from which country you are logging in so i am just giving you some basic steps to resolve this issue but I highly recommend you to contact the help center during office hours. I also attached screenshot on the phone number you can contact for your issue.