Extrusion of surface in perspective

I have a problem with the extrusion of a selected surface in perspective. This is my object:
Bildschirmfoto 2021-03-02 um 19.23.17

I then select the top surface, which I want to extrude to make the object higher:
Bildschirmfoto 2021-03-02 um 19.22.57

… and extrude it in perspective view. But it doesn’t extrude perpendicularly, but slightly tilted:
Bildschirmfoto 2021-03-02 um 19.23.24

I have to go to either front or right view to extrude perpendicularly. Is this normal?

Also I noticed with this object, that when I change from one view to another, let’s say right to front, the gumball is for the fraction of a second slightly tilted as well, before it adjusts itself.

I am working in Rhino 7 for Mac.

Anybody an idea what’s going on?

Thanks in advance - best - Jan

Is your gumball is set in screen projection mode?

I’M not completely sure what screen projection mode is. These are my settings:

Another problem I have sometimes is seen in this screenshot: the third (blue) arrow ist missing.

… and this ist the other problem: the slightly tilted gumball when changing from one view to another:
tilted gumball
I can’t help but feeling this must be a bug …

Hello - - Andrea is spot on… set the gumball to align to Cplane


I did that – yes! That was it, thanks a lot!