Frog, don't forget you can use the APP called Stacer! You can find it in the software store, it should be there.
Stacer is great, you can get good info on the Dashboard itself. Then you can get more detailed info, from the different tabs on the left side. Stuff like a process monitor, internet speed monitor, etc. You can even clean out the temporary files too with it, its a lovely tool.
A new APP I recently installed, which reminds me a lot of the Windows system monitor, is the Mission Center APP.
This tool has some of the same abilities, and might be useful to you as well, depending on your needs. And I like it more then the built in system monitor in Zorin OS as well.
FYI, those of you who have gigabit speeds, are so lucky! It literally took 2-decades, till my cable provider, finally provided me speeds worthy of 4K. This is the best I can achieve for supposed 500MB internet.
A lot of network straining happening around here as you call it, everybody shares off the same main cable line off the power poles, and they split it off to each house. Coax cable will always be behind FIOS fiber optics. And since the provider owns a monopoly, they prevent fiber optics from being installed in my area, so I am stuck.
Its either this, or super slow wireless internet, which can't even keep up with 4K demand, so I won't go the rout of 10MB dish net, screw that!