My Dell Laptop running Windows 10, with a Realtek Wifi adaptor, is experiencing intermittant problems in my Deco S4 Mesh network. Every other node on my network works perfectly (several iOS devices, a MacBook Air and a Roku).  

My ISP is Verizon FiOS with 100 mbps up and down.   My Deco is plugged directly into the FiOS modem, not into a Verizon router.  My Mesh network consists of 2 Deco S4 units.

The problem is that the Win10 laptop frequently (at least two or three times a day) experiences downgraded speeds.  Speedtest.net will show download speeds of 2 to 4 mbps and, interestingly, upload speeds of about 30 to 40 mbps.  Whenever this happens disconnecting and reconnecting the Wifi on this node reliabily gets me back to a bit over 100 mbps up and down.  This problem, though occuring intermittently, shows the same characteristics just described every time it happens.

I have updated all drivers from Dell on the laptop and ensured I have the latest firmware update on the Deco Mesh network. I have tried a few Windows settings such as disabling autotuninglevel and turning off delivery optimization.  On the Deco network I have tried disabling the beamforming feature. I have ensured that the laptop in question is connected to the closest mesh node before disconnecting/reconnecting.  I have tried turning off the Mesh option for the laptop in question.   All to no avail.

This event occurs reliabily when I wake it up from sleep in the morning. But I can't say for sure it is only related to having woken up from sleep since it happens during the day as well and it's not always clear when exactly the download speeds have gone from 100 down to 2 or 3 mbps since I am not constantly running speedtest -- having other things I want to do with my computer.  

Does anyone have any ideas on how to make my network perform reliably, without interrupting work on my laptop multiple times a day.   I have searched various sources -- Dell support included -- but have not found anyone describing a similar problem.

The consistency of the problem, when it occurs, and the fact that upload speeds are healthier than download may be important clues.