If your screensaver keeps displaying the same old content even though the source page has updated, your browser or a server in between is serving a cached copy.
To fix this, add %%CACHEBUSTER%% anywhere in your URL — usually as a query parameter at the end.
For example, change https://example.com/news to https://example.com/news?cb=%%CACHEBUSTER%%
Every time the screensaver loads the page, %%CACHEBUSTER%% is automatically replaced with a unique value, which makes the URL look new and forces a fresh fetch.
URLs without the placeholder are loaded normally, so you only need to add it where caching is a problem.