No idea if this has been reported and it is really minor. I run Chaos/Dual Pistols.
I can see both Pistols on my toon (either in my hands or on my hips) unless I have used Chaos abilities and then I switch to running or otherwise put chaos away. At that point only the holstered left hand pistol is shown.
I’ve only tested this with Chaos/DP. It would be interesting to see if this is also the case if Pistol were primary, or for toons running something else primary and DP as secondary.