I'm working on a model that has several configurations and at some point while flipping to a different configuration another flexible subassembly suppressed every single mate and the parts were hanging out in space. I didn't notice it at first and had already made changes and saved. So then I had to touch each part and unsuppress the mates manually which took a long time.

So my questions are:

1. What could I have done without realizing it to suppress every mate and explode a portion of the model this way?
2. Is there a way to freeze mates of a flexible assembly so they can't be unsupressed?
3. Is this bulk mate suppression a feature?

Thanks for you help in advance!