Save and reload to unload customers (they don't save to file)
Avoid selling to shield customers though it isn't limited to shield customers there's a good chance any customer that asks for multiple weapons would also trigger it but I haven't seen a multiple-weapon order yet - I just know there's a stat for it.
it happens sometimes just save and reload. btw if you hava alot of weapons premade set up on the counter its pretty nice when this does happen becasue alot of the stuff you might have had up there a while will most likely sell. i once sold my entire stock in 10 seconds because of this lol
