some more information - i tried a different laptop sitting in the same spot as my Dell - monitor still on and the wifi speed on that laptop is double - to around 300Mb - so there is definately something wrong with my new Dell wifi Update-Resolved-hi thank you for trying to help - i have a feeling this whole issue was because my ISP was changing my plan - I cant explain why it seemed so consistent an issue with the monitor connected, but right now i'm getting the speeds I expect and it seems like its ok.  
Through trial and error, I have noticed that when my monitor is plugged in, the wifi speeds are severely impacted - my speeds normally around 200Mb, with the monitor connected and on, speed drops to about 50Mb. I got a new cable, and it did not fix the issue.  I got a hdmi to usb-c converter and while its better - around 130Mbish, its still not full speed. Is it the port, or would somehow my monitor be causing the interference ? Its not like its some old CRT big bad thing - its a Dell P2411, a few years old. I have tried a bunch of other things i've seen via the googles, like disabled SmartByte app, to no improvement.  
My hdmi port seems to slow wifi severely