We just performed an upgrade to Betheme 21.5 and could it be that this version contains a bug regarding the banner option?
We added banner code which used to work fine through:
Betheme -> Theme Options -> Header&Subheader -> Extra's -> Other -> Banner
But it seems that after the betheme upgrade, the banner is not showing anymore.
I also tried with other html code to get a banner showing but that doesn't seems to work either.