bad request

This happened last year and your suggestion was to clear cache, which I have done, still getting bad requests:

[2020-10-23 11:46:34] API.INFO: Contact set to be created ["Extra information",[{"form":"Newsletter"}]] []
[2020-10-23 11:46:34] API.INFO: ConstantContact_API::add_contact:527  - http.status.bad_request - Bad request. [] []
[2020-10-23 11:46:34] API.INFO: Submitted contact data ["Extra information",[{"email___ecd412e904309dcce66177488240b016":{"key":"email","val":"***@verizon.net"},"email":"***@verizon.net","first_name___185b795264e09a98fe0f4e47e70e8e90":{"key":"first_name","val":""},"lists___6d0ef0390d8c8bd7f8619fd5e458e8c6":{"key":"lists","val":""},"list":["5"]}]] []
[2020-10-23 12:19:11] API.INFO: Contact set to be created ["Extra information",[{"form":"Newsletter"}]] []
[2020-10-23 12:19:12] API.INFO: ConstantContact_API::add_contact:527  - http.status.bad_request - Bad request. [] []
[2020-10-23 12:19:12] API.INFO: Submitted contact data ["Extra information",[{"email___ecd412e904309dcce66177488240b016":{"key":"email","val":"***@hotmail.com"},"email":"***@hotmail.com","first_name___185b795264e09a98fe0f4e47e70e8e90":{"key":"first_name","val":""},"lists___6d0ef0390d8c8bd7f8619fd5e458e8c6":{"key":"lists","val":""},"list":["5"]}]] []
[2020-10-23 12:52:59] API.INFO: Contact set to be created ["Extra information",[{"form":"Newsletter"}]] []
[2020-10-23 12:52:59] API.INFO: ConstantContact_API::add_contact:527  - http.status.bad_request - Bad request. [] []
[2020-10-23 12:52:59] API.INFO: Submitted contact data ["Extra information",[{"email___ecd412e904309dcce66177488240b016":{"key":"email","val":"***@HOTMAIL.COM"},"email":"***@HOTMAIL.COM","first_name___185b795264e09a98fe0f4e47e70e8e90":{"key":"first_name","val":""},"lists___6d0ef0390d8c8bd7f8619fd5e458e8c6":{"key":"lists","val":""},"list":["5"]}]] []

The page I need help with: [log in to see the link]