1803 update - WiFi Slow

The April Microsoft update is now available.  Update to version 1803.
I have now updated a couple of the Lamas HQ systems, including mine and the Network Managers'.

The systems I have updated so far have happened apparently successfully.  (fingers crossed or your superstition of choice!)

When I say successfully, I mean that the system has done the update and rebooted and then has gone on to work.  No reboot loop or blue screen equivalent, Automatic repair loop or such like.  There are different degrees of successful!

What I have noticed is that my laptop internet connection is slower than a slow thing going slowly.

A major update like this is usually followed by a Disk Clean-up and a driver update and maybe a malware, rootkit and full virus scan to just complete the job.

The Driver update, didn't make any difference.

I found a website that gave some ideas about post 1803 installation but it suggested installing a driver updater that a) gave me exactly one scan then started demanding money to go any further and b) is showing up on Malwarebytes as (Surprise!) a Potentially Unwanted Program!  So it was an Advert rather than an informational piece.

Malware scan found the PuP as above, and the brilliant and marvelous resources on  BlackViper detail the services required to run Windows 10 without any extraneous stuff.

It was still the same after the services check.

The Ethernet adapter works fine and is giving a realistic and proper speed.
An external wifi dongle, once installed and operational, gave a sensible wifi speed.

Lamas HQ systems have a third party security application installed, which includes both AV and Firewall.  So, the Windows Firewall is disabled.

It appears that disabling the Windows Defender Firewall was my error.  Once I changed the Windows Defender Firewall service from Disabled to Manual, my internal WiFi started working as it should giving more than 10mbps closer to 50!