New to Penpot and found this weird change of object

Hi there,

just tried out the self-hosted version of penpot which is quite laggy and stumbled upon this weird behavior. Luckily I can also reproduce it on https://design.penpot.app/ and made this gif. It is basically a combination of default shapes.

Penpot

Would love to know if I am using it the wrong way or should go about it in a different way. My goal is to draw an arc.