It's not normal, especially since we didn't make any changes to MangledVerb in V4. Is the overall output low (both dry and wet), or is it just the wet output that is low? Has anything changed in your setup since updating? For example: mono/stereo rig? switch settings on the back of the pedal? Expression pdl or lack thereof? Etc.
Thanks for your help. I think I found a solution. I have done a reset and then I entered manually parameters (user patches). The problem happened when I used Factor Lib to restore patches.