If you use our iFrame Resizer script to embed PollUnit, check if there is a Javascript error on your website. Errors in scripts on your website can prevent our script from being executed correctly. Alternatively you can switch to the version without iFrame Resizer.
In general you should check if the PollUnit iFrame is changed by a script or CSS of your website. E.g. the iFrame should not have »scrolling="no"« attribute. If the delivered HTML code looks different than the one we provide, then the probability is very high that a script on your site is causing the error.
The verification can be done with the web console of your browser.