I think it's the same bug i encountered, i reported it. When you removed the inset and explorer style setting, the gauge goes invisible. If you didn't do the same, it's something else and i am wrong.
the status looks like that:
(257/257hp 157/163mn 178/178mv)
this is my trigger:
(&{hpvar}/&{mhpvar}hp &{mvar}/&{mmvar}mn &{mvvar}/&{mmvvar}mv)
if i delete the ) on the end, it works properly, if n ...