What about caching?
If a cache stores the output after Conditional Content has processed it, subsequent requests can receive that stored output without the conditions being checked again. A cache that distinguishes only the URL and language may reuse the wrong content for conditions based on the visitor, device, or date and time.
Configure caching so that requests which need different conditional content do not share the same cached output, or exclude the affected content or pages from caching. Date and time conditions also need the cached output to expire or be refreshed when the condition changes.
Turning off caching for a module affects that module's cache only. A full-page cache, reverse proxy, or CDN may still cache the resulting page. Check all caching layers serving the affected page, and clear existing cached output after changing the configuration.
Strip surrounding HTML tags
When inserting Conditional Content, the content editor might add surrounding html tags (such as div, p, span) to the {show} or {hide} plugin tags:
<p>{show usergrouplevels="registered"}</p>
<div>Your content</div>
<p>{/show}</p>
This can cause unwanted generated output with the surrounding html tags, and therefore adding extra paragraphs or divs before and after your content.
You can prevent this behaviour from happening by enabling the general Strip surrounding tags option in the Conditional Content plugin settings, which will always remove html tags surrounding the {show} or {hide} plugin tags.
Or you can individually override this setting in the{show} or {hide} plugin tags by adding a trim="..." attribute with either a true (on) or false (off) value.
{show usergrouplevels="registered" trim="true"}...{/show}