Windows tile - Work space Area

Hello,
I am running version 2026.3.13.0

I cannot split my working area when "moving" a windows from RDM

While I grab the windows, it opens freely, and does not lets me fit it to left/right or top/bottom

Window just "pop's" out undocked....

Is there a parameter I missed? or something that can be done?

or a time for a correction?

Thanks again for the nice peace of work !!!!