Tiling windows not using the full area.

I just set up a brand new computer, a Mac Studio and fresh installs of everything, but have not installed any window manager software this time, and it’s still doing it. When I have the application frame turned on, tiling fills the space, but when I have it turned off (as I prefer), tiling doesn’t fill up the open area.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~Disclaimer~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ The information contained in this communication is confidential. It is intended solely for the use of the individual or entity to whom it is addressed. Others are prohibited from taking note of or taking action with respect to the content of this information. If you are not the intended recipient you are hereby (a): notified that any disclosure, copying and/or distribution of this information is strictly prohibited and may be unlawful, and (b): kindly requested to inform the sender immediately and destroy any copies.

Cole Haan LLC and its affiliates do not accept any responsibility and/or liability for the improper and incomplete transmission of the information contained in this communication nor for any delay in its receipt.