Issues with Arris SB8300 Modem

Anyone have issues or tips with this modem? A family member has this for when I visit, and in the last few months it's been cutting out, sometimes multiple times a day. Based on an old forum post, I tried adding a splitter; usually that hekps for a few days, but then it goes back to cutting out, remove the splitter, works for a week, cycle ad nauseum. Unfortunately the modem is out warrenty.