Hey Adam,
Thanks for the post you've written back in March 2020. I did what you said and unfortunately, my Wi-Fi would still disconnect on a frequent basis. I was really close to giving up but told myself to continue the investigation.
I then noticed something. Every single time the Surface Pro 7 would disconnect, my mobile phone who's also connected to the same home Wi-Fi would also disconnect at the same time.
I then thought about connecting the Surface Pro 7 to my 5Ghz internet connection instead of using the 2.4Ghz like I used too and since then ... NO MORE FRICKEN RANDOM DISCONNECTS!!!!
Working with the Surface Pro 7 without having to fricken manually connect to the Wi-Fi 4-5 times an hour is absolutely amazing!
I'm not a tech guy and don't know the reason why it works but it did for me.
Cheers mate!