Melee bug since Old Blood update

[I3etrayer]

Me and a group of friends were doing a T3 Relic defense against the Corpus and everything was going pretty well until around wave 15. Right around there -- two of my friends and I lost the ability to melee except for the heavy attack slam. It was around the exact same time and we were using far different weapons so we weren't too sure how the bug came about. We couldn't use the light melee or the heavy melee charged attack, it'd always go to swing before resetting to base position without connecting or doing any damage. Switched to operator form and died in an attempt to fix it, but nothing solved it. Is this a known issue and if so is there any fix for it?