More than bugs, it was OP. It wasn't a "defensive" stance, it was an "A move offensive stance".
1-You can block the access to a 2nd 1919 but leave the option for a Bar/Zook pick up from rack. Requires tech and adjusting the BAR to be more of an AR wouldn't be OP (no one picks atm bars if they have 1919 and the combo wouldn't be strong).
2-If no other weapon from rack can be picked, then you can increase the performance to be a bit higher than now and lower to LMG34.
3-Leave performance as is, limit to 1 (with either option 1 or 2) and give defensive stance a return WITHOUT SUPPRESSION. Long cooldown, non toggleable during combat, which grants def/off buff.
1- I'm sure some more casual or amateur players would love this to be allowed, many people do quip about a single bazooka on each squad makes the "rifle blob" anti-everything, I dig it.
I prefer BARs myself because I like to always be moving.
2- Compare the 1919 to the Grenadier LMG42 and see that the one from the racks actually costs more munitions, the issue only appears when you can double equip them, which means a bigger investment or a huge lead on munitions.
3- But without surpression, what's the trade-off from mobility? I know Rifles can't fire them on the move, but standing still is dangerous, with how many powerful one shot grenades the Nazis have.