Thanks after many hours trying to fix the mobile logo fixed "height" default, i found your post and fixed my issue.
Xenforo have to check this and implemented by default i think,
having same issue, where did you paste the css code? i guess i figured that "set height and width" setting on the logo options was intended for this but its just SUPER tiny on mobile now.
edit...found this...didnt realize it needed to go in extra.css thanks to the forum for the fix!