Several Issues with Latitude 7490

I have a Dell Latitude 7490 that I just got recently as a used machine and I am having several issues that I need help with.  When I bought the machine it did not have a hard drive (SSD) or a battery. I bought a m2 NVME SSD installed it and installed windows. and for the most part it worked fine.  During the time since I installed windows I had two issue.  The first is after I booted the machine up the first time I opened Firefox and it tried to go to my Home Page (AOL Mail) it would take down the cable modem/router.  I would have to restart it and then everything worked fine with Firefox and going to the home page until the next reboot. If I run Firefox in troubleshooting mode it does not cause the issue. The next problem I encounter may be a fore bearer to the last and most critical issue I have experience. I would randomly get a BSOD with the message "Your device ran into a problem. We're just collecting some error info ..." only it just hung at that point.  At the bottom of that screen it referenced going to www.windows.com/stopcode WHEA_UNCORRECTBLE_ERROR. I went there an it says there appears to be a hardware issue and indentifies areas to look at. Nothing I did seemed to rectify the problem.  Yesterday the new battery came in and I installed it. But after I installed it the last and most serious problem come up and it is that I cannot get the computer to recognize the NVME SSD at all.  I have changed at the settings in the BIOS that I have seen reference it different posts in this forum, but nothing seems to work. I have taken out the battery, and tried it and it still doesn't work.  I am lost at this point. Thanks in advance for any help on these issues, even if it is to redirect me somewhere else.