Unable to disable rules in WAF

I am trying to disable rules on the WAF on one of my client's sites. (I am added as a member).

I click the toggle switch and receive an error:

exceeded the maximum number of rules in the phase http_request_firewall_custom: 17 out of 5 (Code: 50001)

exceeded the maximum number of rules in the phase http_request_firewall_custom: 17 out of 5 (Code: 50001)

exceeded the maximum number of rules in the phase http_request_firewall_custom: 17 out of 5 (Code: 50001)

exceeded the maximum number of rules in the phase http_request_firewall_custom: 17 out of 5 (Code: 50001)