Slic3r: 1.3.1-dev-54a31ee
OS: Ubuntu 18.04.4

Load STL
Select model.
Right click - Rotate - Around z axis...
Input 90 - press ok
Model moves 90 degrees counter clock wise as expected.
Input 90 - press ok
BUG Model doesn't move.
Input 0 - press ok
Model doesn't move. (As expected for relative rotations, but not absolute.)
Input -90 - press ok
BUG Model rotates 180 degrees.

Around x

There should be an option to specify the port of the HomeKit server.

HomeKit also uses Bonjour, which uses port 5353.
This should be documented in the Readme.

I'm absolutly new on this area.
So firat thx to all, you make a great job.

Maybe i will buy a Alfawise U20 Plus and so it is very interessting for me to know if i can use the 'normal' U20 config? Or did i need an adapted or complitly new config.

In the first step, i think i don't buy the BLtouch. But maybe a few weeks/months in the future ;)

Maybe anybody have a config for the U20 Plus? Would y