Win10 capping internet at 20%

Having an odd problem.
Win10 latest insider build appears to be capping my internet at 20%.

If i run ookla speedtest through chrome or ms edge i get close to my full 1 gig connection up and down.

However if I run the ookla app from windows I barely hit 200meg.

I have tried multiple network resets and every possible suggested tweak google has offered with no change.

I have 2 other pcs and they both give similar speeds in bot the browser and the app.

Is there any way to do a scorched earth reset ?
Wipe out everything and start with factory settings for services, registry, network card settings ?

Are you saying you're running the Desktop version of Ookla's Speed Test?

If so, are you hitting the same test servers as Edge and Chrome?

Exactly.
When I run Ooklla through chrome through a browser like chrome on edge it gives me close to my 1gig speed.
I run the Ookla desktop app and I get approx 200meg.

Only difference I see is the browser shows multiple connections and the desktop shows single.

My motherboard is an Asrock z730 Taichi Ultimate with 3 NICs.
ASRock > Z390 Taichi Ultimate

AQUANTIA® 10 Gigabit LAN
Intel I219V and I211AT

The Aquantia is wired directly into a port on my router, Pace 5286AC
The two Intel connections are connected into a switch which is then connected into another port on the router.

My wife's PC is using a single connection, directly into the router and she is getting roughly the same speeds regardless of using browser or desktop Ookla.

I have tried every ting I can think of to reset my networking, every 'trick' I can find on google, nothing has had any impact.

I REALLY don't want to do microsoft's usual 'fix' of "just reinstall windows completely from scratch".

So, any and all suggestions and ideas accepted.

If I had hair I'd be tearing it out.

I said in the original post that the downloaded ookla app is showing 200meg while the browser based ookla is approx 900meg.

I would also check that whatever security software you're using is not scanning traffic on the Desktop Ookla app.

Add an exemption for speedtest.exe