Browser takes a long time to accelerate

The problem arose relatively recently:
The first loading of sites takes 20 seconds, after that everything flies as usual!
It is worth closing the browser "Opera or Edge" (X) and immediately open it immediately, again have to wait ... I
cleaned the cache wherever possible, there are no viruses, there are no unnecessary processes and there is nothing to eat resources, the Internet is 300 Mbps, drive C less than half full.

I suspect that this happened after the next Windows update. Updates removed all that are possible ...
Asks WTF ???