I have a ethernet connection and my wifi/internet keeps dropping : I think this is a TYPO. What you meant to say that ethernet is Dropping. without ethernet wifi works fine ?? Please mention model while asking a question . 

Al those setting under ethernet property can only impact speed, they will not drop an active ethernet connection.

Open Run > NCPA.CPL 

This will give you exact error message when disconnection happens. For an example Network cable unplugged, Unidentified network, Or Ethernet completely disappearing from NCPA.CPL

Network cable unplugged : Try a different cable and a different port on your router. 

Unidentified network : Assign a static IP or reserve a static IP for this computer. 

Network adapter completely disappearing : You are either dealing with BAD Hardware or Driver. Most likely bad hardware. 

In case of Bad Hardware repairs could be costly as ethernet jack is usually on Motherboard. I would suggest getting a USB 3 to Ethernet dongle like this which will give you Gigabit ethernet port.  

Thank you! That worked!!!!!

I have a Precision 5530 mobile workstation that was upgraded to Win 11 about 2 months ago.  I tried disabling the two Device Manager advanced property items you mentioned and am still getting network adapter disconnections.  The network troubleshooter resets the adapter and shows the message "the default gateway is not available" as having been fixed.  My WiFi works fine and does not have this issue, but my LAN connection is useless.  After reset, it will stay connected for about 3 - 5 minutes and then automatically disconnect.  My laptop uses a docking station for LAN connection and a USB plugs into the computer.  All drivers are updated with the Dell Command Update app.  Do you have any other suggestions I can try?

I hope this fixed everyone's issues. If you're like me, I still had disconnecting issues post changes. In addition to these changes, In device manager I 'rolled back' my realtek usb GBE controller (my current wired usbc-ethernet connection driver) and it has worked for the past 10+ hours. 

@Pompano​ if you search you’ll find it they are replacing motherboards and a lot of these inspiring 15s but they’re not telling anybody on there they’ve scrubbed the website to take it off, but I’ve talked to two people in the pasture. They replaced their motherboards to resolve the issue. These are the Dell 15 and experience do not have a network adapter. You have to use a USB adapter.

@Pompano​ I’m having the same problem! Why isn’t anyone from this forum answering this question or someone from Dell?! I really am about ready to smash this whole Dell setup!

@AdrianG001​ 

this worked beautifully for me!  Thank you VERY much!   :-)

@AdrianG001​ 

It didn't work for me either.