This has happened a lot of times when I was trying to do a long range takedown with a high magnification scope, during looking down into a clusted area or if the server was experiencing lagging issue that caused the client side's fps dropped down to below 20fps the holding breath seems not working, I realized this when the scope is still swaying really far off just like not holding breath and the character did not breath heavily due to holding the breath for long time period. but this issue never happened in Arma 2 while the fps Arma 2 had is actually a lot lower than Arma 3 so I was wondering if this is caused by the limit of engine