I just saw this one for the first time. Kerillian (as Shade) using a Longbow. She has one of the perks that restore ammunition for critical hits (I believe it’s a trait on the bow, and it’s the +5% of max ammo for crits).
With her last arrow, fired and got a critical hit. Ammo counter then appeared as 0/1, but she would not nock the last arrow without first switching to melee weapon and then back.
This occurred at the very end of Empire in Flames. I’ve never seen this happen before, but I can also see it as an edge case.
That doesn’t mean it’s not a bug. If your ammo get’s refilled by traits, it should also restart the reload animation, and not force you to swap to your melee and back.
Although, this specific bug was reported over a dozen times minimum already.