hello
I call this the sprinting at a crawl bug and it's as frustrating as it sounds.
Very few games suffer this problem - if you're running, you're running at the same speed as everyone.
Arma is an oddball in some ways, often for good reason, but at times can bring a standard rig to a crawl and everyone else blows by you like you're standing still.
I wouldn't expect them to look at this as a bug, but you might file it anyway; they've done wonders with the beta and it's a spectacular game otherwise.
I can suggest trying to increase the game's performance. The most obvious is to stay out of the area of too many AIs/players, smoke, etc. The game's nicely tweakable and you can find info on the forum or with a search like: arma 3 cpucount nologs
GL
