While YouTube videos and other iframes are optimized and lazy-loaded by default when using Rabbit Loader, Vimeo videos are not lazy-loaded unless you turn them on. This is done because Vimeo provides additional security features which restrict video viewing on Safari browsers.
Go to Settings -> Page Rules on your account. Click on the modify button for the page rule you want to modify. If you want this new setting to be effective for the entire website, choose the ‘*’ rule. If you are not familiar with it, please read the page rules introduction first.
Turn on the relevant checkboxes and save the rule.
After saving this rule, and purging the cache, the videos will be lazy-loaded or skip lazy loading for matching page rules.
When a Vimeo video has “domain-level privacy” turned on, the video can be embedded and played only on specific websites you want. When such videos are lazy-loaded on Safari/iOS browses, the browser does not send the referrer header and Vimeo fails to understand from which website the request is being made and resulting in restricting the video.
Before you turn on the lazy loading of such videos, please turn off the privacy settings.
You can turn off the domain-level privacy for the video from its settings options. Turning it off will allow the video to be embedded on any website as it skips the referrer header checks.
If this setting is not configured, the video can not be loaded if lazy-loaded on Safari/iOS browsers.