I unfortunately don't have visual evidence of this happening. But I died in between Sanguine Retreat being used, during the short period of time where Mina can activate it again. The bar was now empty, but respawning didn't do anything to reset it. I had to use the ability again in order for it to disappear completely.
If its not clear already, this is not a major bug. I just felt that it was worth reporting.
If its not clear already, this is not a major bug. I just felt that it was worth reporting.