I am using Ghost 3.28 which was installed using Docker container.
My website is https://linuxhandbook.com/ and I am using Auden theme.
I have enabled membership, both free and paid. I have both free and paid members signing up.
In last few hours, I have got at least two complaints of “Please Enter a Valid Email Address” error when trying to sign up for membership. The sign up page is here: https://linuxhandbook.com/signup/
I would also like to add that there are new successful sign ups as well. So it’s happening only for some people.
I have not set up Mailgun because I use MailerLite for newsletter.
What could be the possible reason for this error and how can I fix it? Any pointers would be appreciated.