Titans in Destiny 2 are the most annoying and memed class but even they have a bad day from time to time. Or for five years. One player figured out that the trending Mortar Blast bug was present in a similar form in the original Destiny.
Destiny 2 is a place where Titans are usually the ones giving headache to others but this time around they are in need of help. Namely, their Mortar Blast talent from the bottom Sunbreaker tree, Code of the Siegebreaker, modifies the melee ability to discharge a solar explosion that sets enemies on fire.
It would be all nice and dandy if the ability wasn't actually saving enemy lives. In high octane situations, such as duels in PvP, players often rely on their melee to finish an opponent off. However, Mortar Blast sometimes prevents any melee damage on an enemy and only sets them on fire for minor damage over time.
Back then, the perk name was Thermal Vents and it had a similar function. Then again, it wasn't only the function that the two shared as the bug was in place back then. Just in case you need visual representation, here is a video of the weakest punch in Titan history.
Bugs happen from time to time and Bungie usually disable and item or two while it gets sorted. Therefore, they normally aren't a big deal but having a bug that can ruin a player's experience active for over four years is something to raise an eyebrow at.