I have two subscriptions two different calendards, one is refreshing, the other one not.
I checked the http headers for the different subscriptions and found out that the working one has several cache related http headers set:
< HTTP/1.1 200 Apple WebObjects
< Server: nginx/1.19.2
< Date: Tue, 27 Sep 2022 06:14:34 GMT
< Content-Type: text/calendar
< Content-Length: 11496
< cache-control: private, no-cache, no-store, must-revalidate, max-age=0
< expires: Tue, 27-Sep-2022 05:32:39 GMT
< pragma: no-cache
< x-webobjects-loadaverage: 52
< X-Varnish: 156865840
< Age: 0
< Via: 1.1 varnish (Varnish/6.3)
< X-Cache: MISS
< Accept-Ranges: bytes
< Connection: keep-alive
Could this be (part of) the problem?