I am getting packetloss, and high ping spikes, too. I have been in contact with them via email for a while and have not gotten close to any fix, switched modems, routers, ethernet cables, splitters. You name it, I have done it. Had over a dozen techs and linemens to tell me there is no issue. Kinda sad, from my experience, you are just going to have to keep contacting them, and we might just have to accept that this will be our experience with cox, till they acknowledge this is a real issue.
Have had the same experience, finally got them to change the outside line after the fifth visit, whcih fixed packet loss but still high lantency. They still arent coming into homes so may have to wait until them. Dealing with cox is the worst