URxvt runtime font changes buggy with tabbedex

[mnzaki]

I have a shortcut to change urxvt font in runtime:
URxvt.keysym.C-S-plus: command:\033]50;xft:Terminus-12\007

If I use it when I first open urxvt, it causes the font of the tabbar to change instead of the font of the actual tab.

If I type anything and then use it, the screen is blanked completely and will not come back unless I change the tab and return to it again (even if only one tab is present, I must issue a tab change command)