If you check the Qlik Sense release note (for the one version you are using), you would find a list of all know bugs/issues. And for reporting it, refer: Re: How to report a bug?
Go to qlik.com and click the Support link to get to the Support page. There you'll find contact numbers to contact support by phone and an online case portal.
As a partner, you will need to create a support case using the Support portal (www.qlik.com/support). The pieces of information that we will eventually need are:
- Description of the issue and how it is unexpected behavior
- Details of the version that you're running (i.e. 2.0.6 vs. 2.1.1)
- A way to replicate the issue on our end for R&D to take a look at it. As simplistic as possible is ideal.