I used to change the default proxies on my starter plan but now they all greyed out and only available on the Flexi plan? Since when did make this change?
Premium proxies have been available only in Professional and higher plans for years now. Checkout https://distill.io/docs/web-monitor/monitor-webpage-using-proxy-servers/#applicable-plan-and-pricing. That being said, there was a bug about 2 months ago where anyone in free plan and above could have used any of the premium proxies.