Hi,
I had something similar to this happen to my computer. Now this may not help, but I thought I throw it out there anyway. Can I assume the specs above are for the computer getting the slower speed? If so I see you have an MSI motherboard, do you have Dragon Center installed? I found a little piece of software probably install by me by accident because I assumed it had something to do with the internet software, but it basically crippled my internet speed. So my older Intel computer was getting 500-600/Mbps, but my newer Ryzen Machine with an MSI X570 MEG ACE motherboard was only getting between 200-300/Mbps.
It wasn't always like that and I must have again installed this later. Anyways go into Program and Features in Windows and look for something called, "cfosspeed." Again it maybe something else, but I know once I uninstall every aspect of this software my Ryzen computer is now on par with my Intel. Oh, it mainly affected download speed and not upload, which from what I've read of your post seem pretty close.