Steam not maximizing?

My steam isn't maximizing correctly. Pics below pretty much explain it. Monitor config == 1 1920*1080, 1 1080*1920 (portrait)

floating window

Maximized window?

It doesn't like Portrait mode. It wants to be wide not long.

well shame on it... I don't know why it won't obey when every other program does...

is it in mini mode?