What exact version of AEM 6.4 do you have? Can you try the latest SP? One more test, if you drop the campaign component to your template, something Text and Personalization (Campaign) component, do you see campaign variables?
"why I should I monitor the CQ-number although I get notified via an update of the case" - that is not what I've explained to you. While working on the case we will let you know to what service pack the code fix will be added. SP release date can be located at https://helpx.adobe.com/experience-mana...
Well, our established process is to wait up until we know to what SP release the code fix will be included. Support has to share this information in the case's notes. As such you will know for sure the SP release date.
The package manager has been deprecated in favor of a Software Distribution:https://experience.adobe.com/#/downloads/content/software-distribution/en/general.html
In case you have Adobe Analytics, you can employ AEM page insights https://docs.adobe.com/content/help/en/experience-manager-64/authoring/page-performance/pa-using.html
The support case remains opened up until we get a confirmation from the engineering team, that the code fix will be a part of the scheduled service pack. AEM Product Update Releases Roadmap can be located at https://helpx.adobe.com/experience-manager/update-releases-roadmap.htmlA service pack releas...
Allowed templates for experienced fragments should be set for XF root folder, for example at /content/experience-fragments.You need to define cq:allowedTemplates property as Sring[] and set all available templates there, example:/libs/cq/experience-fragments/components/experiencefragment/template/co...