How can I temporarily unroot my S6 on OS 5.0.2? I downloaded a Play store app that has no audio and after research found out it's because it discovered my phone is rooted. I use Ping Pong to root which comes with SuperSU. I have read the other questions on this topic on here but they are outdated. So is there any way to stop an app from knowing I'm rooted by isolating it in some way?

Also I can't use Rootcloakplus as S6 is not compatible with Xposed.
Xposed is basically the only way. You could try changing the apps permissions, see if that works. Otherwise, you may need a serious tinker to get Xposed working.