mount failed in high temperature, filter crashed down.
this could be applicable to more:
today in the dutch heatwave temps are 30+ degrees celcius and inside my enclosure 50 degrees while printing ASA. The mount gave way resulting in the filter crashing down and thereby ruining a 4 hour print. Luckily I noticed the failure quickly and beside the failed print, no more damage was done.
The mount I used was printed in PLA. On monday (EDIT: tomorrow) I will do a reprint of the mount in ABS and reinforce it with a full circle velcro supporting the legs.
I have been using the filter with satisfaction for half a year, doing occasional prints. However a redesign of the mount might be in place.