BUG REPORT using Convolution Reverb effect, Premiere Pro v 12.1.1
I experienced the following issue.
1 - Finished editing in a sequence, including a lot of audio mixing and effects, using 12 audio tracks. 2 - Duplicated the sequence and renamed it, to begin a new day of editing. 3 - discovered that, in the new sequence, my settings in all instances of the Convolution Reverb effect had changed. This occurred in both clip and track effects. I had to perform a lengthy process of resetting all the effects manually. I was not able to find any reason for this anomaly. Restarting the computer and deleting PP preferences had no effect. This is on a Mac, OS 10.13.4. Only happens after a sequence containing this effect is duplicated.

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Dylan Edwards commented
This happens to me at random, super frustrating. I have several common reverb effect presets that I use in my temporary sound mix often. Seemingly at random, upon re-opening the project, the value for mix will be at 100%, which renders all the reverb effects useless as they cannot be heard and essentially mute the audio.
The only fix right now is to manually delete and re-apply the effect to every single audio clip. Real annoying.