Freerdp mouse cursor changes its shape to X on the margins

I'm running xfreerdp on an arm64. The package version is 2.0.0~git20190204.1.2693389a+dfsg1-2~bpo10+1. Sometimes when I run an xfreerdp instance and then move the mouse cursor to the margins of the screen (left/right/bottom), the cursor changes shape to X as in the attached picture. Please explain why this happens, and how to avoid it?