While playing in Crucible, I noticed the following:
While wearing the Crest of Alpha Lupi ("carry additional ammo for special weapons" perk active), every time I die and respawn, I lose special ammo. Eventually I spawn with NO special ammo at all. It seems as if this was happening for some time, but I started noticing it especially when carrying my new Plan C. I start the match with ~30 rounds, then the respawning and losing ammo starts.
This bears some passing resemblance to the Heavy Ammo glitch.
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Any "additional ammo" perk on armor causes the glitch and always has. It's just most noticeable with heavy ammo.