You haven't given me much to go on, but I'll try my luck suggesting a solution.
There may be a couple reasons. Typically this is cased by a user inadvertantly turning off the option to "Save Feature Replay Data". If Feature Replay data is missing, with each update, the Feature Replay data is recalculated causing an update.
Before NX 12, I found a very rare case were a blend feature was not storing Feature Replay Data. When users turned off the Sew option in Face Blend and Aesthetic Blend, Feature Replay Data was not being saved so the blend feature would contininously recalculate its Feature Replay Data. In NX 12, simply Renew these Blend and the unexpected updates will cease.
This is what I recommend,
- Always use Sew option in Face Blend
- Alsways use (and do not change) the Save Option, “Save Feature Replay Data”