Internet Constantly Disconnecting?

I am connected to the router with a cable , a router which my internet provider supplied me with.The problem used to happen before , occasionally , but the disconnecting has drastically increased lately , and these days it has become unbearable , it occurs at least once every hour , especially when i'm playing a game online or so.The disconnects last very shortly , or until i reset my router or disable/enable my network in network connections.I have 2 more laptops in the house , connected via wireless , and they've had no issues with this.The first time these problems occurred i was able to fix it just by doing the windows troubleshoot, which lead to an error saying "Default gateway is not available".I found a lot of threads on the internet regarding this issue , and tried all of them but none seemed to work.

I tried downloading newest drivers from my motherboard site first , then from Realtek's site, then deleting old drivers via DriverSweeper aswell , just in case , but it did nothing.I tried changing the Speed & Duplex to 100mbp/s Full Duplex , which has solved the issue for some , but again it did nothing.I called my internet provider , was told to use static IP address and type it in manually and if it didn't work to try plugging the cable into another slot on the router ,And after all those things , i feel like the problems is even bigger now. I now no longer get the "Default gateway is not available" error , and the only solution is to reset router or disable/enable network , which leads to the network being "unidentified" for some time before it connects.