Alright, so I have just gotten to the part where I face off against Alduin for the first time after learning the Dragonrend shout. The shout works fine, it brings him down and I'm able to damage him (this is not about the health bug). The problem is, when I "kill" him, he actually dies completely...

Instead of starting a conversation and flying away like he should when his HP is depleted, he just initiates a death animation which takes like 10 seconds, falls to the ground like any other slain dragon and then nothing more happens. I am able to loot him and Paarthurnax is just sitting on the cliff behind me telling me to use the Dragonrend shout before Alduin consumes me.

So now I'm stuck since the quest never gets completed. Have anyone had this happen before? I have been searching for a fix, but I can't seem to find others having this bug. Any help would be appreciated - just let me know whatever information you would need to help me!