Shopify custom page meta title and description reverted after a theme or app update
You set a meta title and description on a custom page (About, a landing page), then a theme publish or an app reset it back to Shopify's default — or to an old value — without telling you. Page SEO fields live as metafields with no version history, so Shopify can't show you what changed and has no native undo.
Step by step
Pin down what touched it: a theme publish, a page-template app, or an SEO app with a title/description template. Pause that app or hold off on more theme work first, or it re-applies its own version on the next run.
Re-enter the correct values under Online Store > Pages > [your page] > Search engine listing > Edit. Pages aren't in Shopify's native CSV export, so if you use Matrixify you can re-import the Title Tag and Meta Description columns from a pre-change export; otherwise this is manual.
Re-publish, then recheck the page a few hours later. If it flips back again, an app rule or theme template is still re-applying it on a schedule — disable that specific rule instead of re-editing on a loop.
Going forward, keep a daily snapshot of the meta title and description on every page (custom pages, not just products) so you're alerted the moment a theme or app resets them, with the likely culprit named, and can restore the right version in one click.
Source: Shopify Help Center: editing search engine listings; Shopify Community theme-migration / page SEO threads
SEO Vault keeps a daily snapshot of every SEO field on your store — meta titles, descriptions, alt-text, tags, handles (products AND collections) — and emails you the moment something changes in bulk, with the likely app responsible. One click restores yesterday's state, just the SEO fields. Free to monitor and get alerted; $14/mo for 1-click restore.