ARAM Darius with no passive and unable to ult

I recently played an ARAM game as Darius. I don't play him much at all so at first i didn't notice that something was wrong. The first time I ulted it worked, killing the enemy Kalista. I didn't get to make use of the reset and it went on cooldown. The next time I tried using my ult and it's at this point I took notice. I was unable to ult the enemy standing right in front of me. I thought it could be lag, or maybe they were actually out of range. Later on I was alive for at least 3 seconds, standing directly in front of an Irelia. I had time to check my ping, that i was pressing R, that my ult was definitely off cooldown, and that I wasn't stunned at any point (Darius was just basic attacking the whole way through). I managed to press R about 7 or 8 times and nothing happened at all. No damage, no animation, no cooldown.

As the game went on I started looking for what could be wrong. I noticed that, throughout the entire game I hadn't seen my passive stack a single time. Darius' passive isn't hard to miss, especially against 5 enemies at a time against a background of mostly white, washed out colors. By the end of the game I managed to successfully ult 1 more time out of at least 10 attempts, on the Irelia who was too healthy to be killed by it.

TL;DR: Passive never applied at all Ulted once at the beginning, reset expired (Bought Black Cleaver...?) Unable to ult at all Finally able to ult at the end, maybe linked to it not being a fatal blow