I encountered several bugs in Hearts and Minds. During the glider phases, my glider would not open many times forcing me to repeat the fight. This was mostly during the 2nd and 3rd glider phases.
The more pressing bug was when Mordremoth up and disappeared. This was at the end of the fight, when you use the rift to break the break bar and attempt to kill him. After breaking the break bar, I managed to get his health all the way down so that his body fell down, but my character still yelled that he had recovered. After that, both the rift and Mordremoth’s body disappeared. I attempted to die to try to progress, but didn’t work.
The screenshot should show the story’s objective telling me to destroy Mordremoth but with him not there.