Never Cache User Agent(s)
The option is used to prevent cached and optimized pages from being served on certain devices and in certain browsers.
The User-Agent request header is a string that lets servers identify the operating system, vendor, and/or version of the browser that accesses a page.
You can exclude certain User-Agents from being served cache by adding the string value in the Never Cache User Agent(s) text area in the Advanced Rules tab:
Mobile/15E148 Safari/604.1 string can be added as:
Exclude a specific browser, as in the example:
Add a device name, as in the example:
Wrong display on tablet
Please see the article for possible solutions:
Heads up! Some exclusions added here can disable caching for almost all browsers; e.g.
(.*)Safari(.*) will match any browser that includes "Safari" in the user agent.