Thanks for opening a support topic. Does the same occur if you temporarily switch to another theme? Rather than actively switch to another theme in order to check you could use the Health Check & Troubleshooting plugin, by following the steps below:
- Install and activate the Health Check & Troubleshooting plugin.
- Navigate to “Plugins > Health Check & Troubleshooting > Troubleshoot”.
- From the same screen click on the “Available Plugins” tab at the top right and then click on the “Enable” option next to “AMP”
- Visit your site once more, by opening any AMP URL
- Visit your site once more, as a core theme will be active I suspect the issue will no longer occur when you check any AMP URL
- Switch themes using the “Troubleshooting” open from the admin toolbar, checking does the issue only occur using your current theme. I created a video which you’ll find here, demonstrating how to switch themes while in troubleshooting mode.
Have you also considered using any of the alternative AMP reader themes other than the legacy reader theme? If you don’t see any to your liking you can add your own theme from the list of AMP compatible themes to the reader mode selection of themes.