Purchasing the new 3.2k item Express Shot and using paradox's 3 ability (Kinetic Carbine) causes floating blue orbs and gun particles to appear on the map that don't seem to despawn.
Not tested in live game, just firing range + explore map.
faced the same issue. tested it out for a bit-and this bug is caused by any character, if they use items, that add extra particles when shooting (Mystic Shot, Lucky Shot) with Express Shot. They do despawn when changing character tho.