Across computers and browsers, I have had PAINFULLY slow Goggle Drive Uploads for the past three months. It's like you have to pause, and wait 30 seconds for commands to execute. The same is true with right-clicking in Goggle Drive, or doing almost anything in Goggle Drive.
I am using Firefox and MS Edge. MS Edge is even worse. I also get a webpage yellow bar that says, "A Webpage is slowing down your browser, what would you like to do?" There are stop and wait options. If you do nothing the data will eventually download. Clearing History and Cache does nothing.
The most important thing to say, is that I have no speed problems at any other websites, or downloading or uploading to any other sites, or from any other sites. These remain fast. Furthermore, Goggle Search is great, Goggle Docs composing, saving, and editing is great. But on uploading data to Goggle Drive's server, it is slower than snails. Goggle Downloads can be slow at times, but not nearly as slow as Goggle Uploads.
The observations that your employer's local office suffers the same slow Google response times while connected over AT&T's network pretty much rules out the fault being in Spectrum's transport network. I suggest you run a tracert to Google and look for hops with hefty ping delays.
However, if this condition started on Wednesday and is OK now, there's a good chance that lots of shared VPN server farms were heavily overloaded by high traffic volumes because so many people in the midwest were working from home. THAT situation needs to be reported to your department managers and corporate IT staff so they can contract adequate contingency network resources.
Some speed improvements on Google Drive uploads on Windows 10 desktop. Horrible slowness on Google Drive on Windows 8.1 laptop.
Favor to ask: If anyone is running Windows 8.1 on a laptop and has a Google Drive account, please upload some test files and report the results in terms of speed in this forum. I think Google did something on their end that Windows 8.1 does not like. This is because I am getting that "A Webpage is slowing down your browser" yellow bar, every time on these slow Windows 8.1 file uploads to Google Drive.
If somebody contacts Google about this, and gets anything other than a scripted response, please post. Google Drive uploads on Windows 8.1 is now so slow that it is impossible to use.