Expression Builder in K2 for SharePoint Designer

1. Created an expression in an outcome. Saved it.
2. Opened expression again to add one more condition. Looks fine so far.
3. Added one one more condition. Saved it and clicked OK to complete outcome configuration.
4. Opened outcome and the expression again. The condition that I added in step 3 is gone.

This is happening randomly. Is this some kind of bug? Screenshots are attached.