CLS Guard Troubleshooting
2026-03-016 min read
CLS Guard Troubleshooting
This guide covers common issues specific to Sera CLS Guard and Sera AI CLS Guard.
CLS Score Not Improving
Check if CLS Guard is Active
- View your page source (right-click > View Source)
- Search for
sera-cls-guardin the HTML - You should see a
<style>tag with CLS Guard CSS rules - If not found, the plugin may not be loading on that page
Ad Network Conflicts
Some ad networks inject their own layout shift prevention:
- Google AdSense Auto Ads: May conflict with CLS Guard's ad pre-sizing. Try disabling CLS Guard's ad pre-sizing and let AdSense handle it, or vice versa.
- Ezoic: Has its own CLS optimization. Disable CLS Guard's ad features if using Ezoic.
- Mediavine: Generally compatible. If issues arise, add Mediavine's ad containers to CLS Guard's exclusion list.
Theme Conflicts
Some themes have built-in layout shift handling that may conflict:
- Temporarily switch to a default theme (Twenty Twenty-Four)
- If CLS improves, your theme has conflicting CSS
- Add the theme's CLS-related CSS selectors to CLS Guard's exclusion list
Sera AI CLS Guard Dashboard Shows No Data
Cause: The monitoring script has not collected enough data yet.
Fix:
- Wait 24-48 hours for data collection
- Visit several pages on your site to generate CLS data
- Check that JavaScript is not being blocked by a caching plugin or CDN
- Verify the monitoring script is loading (check browser console for
sera-ai-cls-guardrequests)
Learning Mode Not Generating Fixes
Cause: Not enough layout shift events detected during the learning period.
Fix:
- Extend the learning period (default: 7 days, try 14 days)
- Ensure your site has real traffic during the learning period
- Check that the pages being monitored actually have CLS issues
- Try triggering CLS manually by loading pages with slow connections (Chrome DevTools > Network > Slow 3G)
Rescue Mode
If Sera AI CLS Guard's auto-generated fixes cause visual issues:
- Add
?sera-rescue=1to any page URL - This temporarily disables all Sera AI CLS Guard fixes
- Go to AI CLS Guard > Settings > Rescue Mode
- Disable problematic fixes one at a time
- Re-enable fixes that are not causing issues