Hi Renegade,
No splitter, we're both directly plugged into the cable modem. I have found that the issue is not the ethernet wire itself, since swapping it out produces the same problem. Therefore, I have ordered a NIC to install that will hopefully temporarily fix the situation until I can consider getting a whole new computer, probably early next year. I'm not totally against WiFi, we have several devices on WiFi, but I do prefer my wire connection for my main computer as I find it's faster and more reliable.
Mrs.Lufbra