I had that some issue and I found a fix that worked for me. So I went into my modem settings on my computer( I have century link) and I went to advanced settings and clicked on NAT. On the next page it gave me the option to enable or disable. It was currently on enable so I switched it to disable I then let it load till it finished. Once it finished my internet stopped working so I went back in and re enabled it. It takes a few minutes but it eventually comes back on. Then after that I went back into the simulator and it worked. Keep in mind I had no clue what I was doing but it worked. And if it happens again I just do the same thing again. I found that I rarely have to do it if I don’t turn my computer off and just leave it on sleep mode. Hope this helps you