Your sitemap lastmod is lying and Google stopped trusting it

Your sitemap lastmod is lying and Google stopped trusting it
Client's CMS stamped today's date as <lastmod> on every URL, every night, whether the page changed or not. Google clocked the lie fast and started ignoring the field entirely.
Now real updates didn't get prioritized for recrawl because the signal was burned.
The move:
— Fixed lastmod to reflect actual content-change timestamps, not the nightly rebuild time.
— Boilerplate changes (footer year, sidebar) don't count — only the main content body.
— Split the sitemap: fresh/updated URLs in one file, stable archive in another. Helps Google focus recrawl.
— Dropped noindex'd and redirected URLs out of the sitemap completely — they shouldn't be there.
Watch the plugin defaults. Most SEO plugins tie lastmod to "post modified" which fires on any DB touch. Verify it reflects real edits, or turn the field off entirely — a missing lastmod beats a lying one.