Validation on custom fields not working

I have a custom text field I have added a "what is four plus three" question and tried the following validations:

validate[required,custom[number],max[7],min[-7]]
validate[required,custom[integer],max[7],min[-7]]

Neither work and any number can be entered.
How to fix please using JD 4.3 and Joomla 3.7.2
Also Captcha not working even though joomla captcha plugin enabled and Google recaptcha keys entered. > JD configuration > captcha = YES

Hi,
I am not sure with your regex command, but i can help you to figure the issue with Google reCaptcha. Please submit ticket and send your site url with super admin account. I will check the issue for you
Thanks
Dam