Your media could be too moist for its conditions or it may have been overwatered before you bought it. If so then the roots likely rotted resulting in a droopy plant. Furthermore, sealed terrs are typically extremely problematic to begin with. Pathogenic molds/fungi are common in such conditions.

Having the plant collapse like that is usually a sign of a root problem. Touch the leaves it they are dry and brittle, then the plants was kept too dry (despite the drops on the glass), it the leaves are soft then it was the vica versa.

Also if it were mine I'd have a larger drainage layer with a barrier inbetween and a way to take the extra water out of the bottom. That helps keep a healthier terr. HTH.

too warm perhaps.....if kept near a window