Latency spike when not moving

Hey there, for the last week or so. My game’s ping spikes ridiculously whenever I either A) stop moving, either to check gear, bazaar, set skill points whatever. Or B) Even so much as mousing over any other tab open between my monitors. C) Try to Co Op play with my wife on her account.

I’ve reset my modem/router multiple times. Cleared my DNS Cache, nothing seems to improve it. Pretty much to the point, if I elect to do anything that isn’t just running blindly and blasting the game. The ping lag is so bad it’s virtually unplayable.

Thanks in advance for any tips or input.