Cache control is overwritten to PRIVATE

Cloudflare was working fine up until recently. Now it appears that cache control is set to PRIVATE. As per the curl report below:

HTTP/2 200

date: Tue, 09 May 2023 00:35:56 GMT

content-type: text/html; charset=UTF-8

vary: Accept-Encoding

x-httpd-modphp: 1

cache-control: private

host-header: 6b7412fb82ca5edfd0917e3957f05d89

x-proxy-cache: MISS

x-proxy-cache-info: 0 NC:000000 UP:SKIP_CACHE_PRIVATE

cf-cache-status: DYNAMIC

report-to: {"endpoints":[{"url":"https:\/\/a.nel.cloudflare.com\/report\/v3?s=JV5QSf5OpmivAt2pkZLWGZFRr%2BUs6b6deTds8QvaGmTbzuLFdgSKpSroHCAGEjpEOgDSr6Q8fyo5q72H5e6kX6lQTMJvG%2Bb0SDSQzv%2BkX%2F88kcDVyRmaeIaZ%2BppzBZEiS%2FjhmsRPFUCYyr4%3D"}],"group":"cf-nel","max_age":604800}

nel: {“success_fraction”:0,“report_to”:“cf-nel”,“max_age”:604800}

server: Cloudflare

cf-ray: 7c45dd821e981f6e-MEL

alt-svc: h3=“:443”; ma=86400, h3-29=“:443”; ma=86400

Why would this be? Where should I be looking to troubleshoot this issue?

Cloudflare is treating the content as dynamic. The other cache statuses are from your origin server.