permissions-policy header errors, 404 on loading custom CSS

[tkimnguyen]

While viewing https://plone.org/foundation/sponsorship/sponsors/ (happens on other pages too):

Error with Permissions-Policy header: Origin trial controlled feature not enabled: 'attribution-reporting'.
Error with Permissions-Policy header: Origin trial controlled feature not enabled: 'run-ad-auction'.
Error with Permissions-Policy header: Origin trial controlled feature not enabled: 'join-ad-interest-group'.
Error with Permissions-Policy header: Origin trial controlled feature not enabled: 'browsing-topics'.
       GET https://stats.plone.org/matomo.js net::ERR_BLOCKED_BY_CLIENT
       GET https://plone.org/++api++/@custom-css 404 (Not Found)

(the matomo.js error must be due to my browser, Arc on macOS)