connection slows down frequently

[zgrsmsk]

I have a 200mbps  package but most of the time it is 1.7 mbps

professional institution was made and cables were changed

but nothing changed still very slowly

(i have a very fast PC and netgear c6300v2 modem)

[zgrsmsk]

https://ibb.co/XLtQwSZ
https://ibb.co/RYyBvZ1