Question Network problem at home in 5GH - on the computer

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I have fiber optic 600MB speed on 60MB upload
There was a sudden short power outage
Then the 5gh internet was knocked out, it is not clear what it was
I worked on it a bit and sorted it out
On all the devices in the house on 5gh I get the speed as it should be - iPhone, Apple mobile
Streamer, television
But my computer has an external network card on wifi suddenly I get super low speeds at 5gh
I tried to make updates to the computer, for the driver of the card I changed USB locations
I removed the network card from device manager and reinstalled everything
So I replaced an external network card and did this whole cycle and it's the same.
Now I'm considering buying an internal wifi network card and maybe that will fix it
Or am I missing something?
The router has an Asus TUF Gaming AX5400 Dual Band
I have win10
My external network card is from TP LINK
The rest of the products that are connected to USB on the computer
Like keyboard, mouse, external drives work great
I can't put network points on the computer (network cable)
Preferably prefer not to reset the router settings
Because all products in 2.4 disconnect (already happened before)
I would appreciate suggestions and help
Thank youbB