Contrails update every 1.5~ seconds around the your aircraft, depending on speed, often times there's more than one stream. It will also change it's position with you i.e. you go up, your past contrail goes up. Tested on all the player aircraft, minus the heli. An ai T-55 had the same issue although the tanker and awacs didn't. The contrails also inherit the aircraft speed in the opposite direction, so if you flew in a circle, your contrail circle would expand until it dissipated. To my knowledge, this affects all planes. Neither bugs crash the game at all or affect performance, it just doesn't look pretty. Contrails was the only loaded mod when I did a brief test, but I have a few others in the mods folder that were unloaded.
Loaded Contrails and selected free flight quick mission.