WooCommerce Mailchimp subscription failed Error Message

Hello,
I am receiving a couple of dozen error notification emails per day. Can you help me identify / fix the issue? The error emails say:

subj: WooCommerce Mailchimp subscription failed
Body: SS_WC_MailChimp_Handler::maybe_subscribe(): WooCommerce MailChimp subscription failed: User role ‘viewer’ cannot access this request. (ss-wc-mc-api-request-error)

I’ve checked mailchimp, and new emails are being added to my mailing list so the integration does seem to work. I’ve had a look at the plugin error logs and I only have 1 error for today (vs 25 error emails so far received today!). The error in the logs today is:

[2020-04-29 11:50:11] ERROR: Form 22539 > Mailchimp API error: 400 Bad Request. Invalid Resource. md.h***********@pa******************.com has signed up to a lot of lists very recently; we’re not allowing more signups for now
Request: POST https://us4.api.mailchimp.com/3.0/lists/5764413d3c/members – {“status”:”subscribed”,”email_address”:”md.h***********@pa******************.com”,”interests”:{},”merge_fields”:{},”email_type”:”html”,”ip_signup”:”146.185.253.167″,”tags”:[]}
Response: 400 Bad Request – {“type”:”http://developer.mailchimp.com/documentation/mailchimp/guides/error-glossary/”,”title”:”Invalid Resource”,”status”:400,”detail”:”md.h***********@pa******************.com has signed up to a lot of lists very recently; we’re not allowing more signups for now”,”instance”:”a3f42dce-78df-4c0a-a2e7-bd25992fe63a”}

Thank you!