The only time I personally had an issue with the sim CTD’s I did the same as you, I went through every checklist with no luck.
I ended up resetting Windows 10.
It caused me to lose almost all of my saved info, and took a long long time to get everything I had in the PC set back up, but it did the trick.
If you are pretty sure it isn’t your internet, it might be worth a try, but remember, you will lose a lot of info, and there is always the chance it may not work.