Question Keep losing internet access on only my PC.

[InfuriatedFrog]

I had my motherboard replaced a month ago. From the last 3 days My PC keeps losing internet access and it only gets fixed if I restart my PC or use the troubleshooter. The troubleshooter gives different problems. Sometimes it is "network gateway not available" or "Reset the WiFi adapter". This fixes my internet temporarily but then again I lose internet access. I tried many fixes from many forums. I reset my network settings but to no avail. The thing is, My PC loses internet access but my phone or my fire TV keeps working. I'll get a replacement wifi adapter from my friend today. I'll update soon. But please tell me how to fix this !
PS Specs-
Ryzen 5 2400G (no overclock)
GTX 1050ti Mini (no overclock)
16GB DDR4 ram (XMP enabled)
Gigabyte B450M-H
550W PSU
128GB boot SSD
2TB HDD + 1TB HDD

 

[InfuriatedFrog]

Also there is no virus, malware etc. I have used both bitdefender premium and also malwarebytes

 

[InfuriatedFrog]

Also, one suspicious thing, when I am attending online classes or playing games, the internet is being used constantly and at that times. the internet doesn't stop ! But when i am watching YT. when the video gets buffered a lot so the internet is not being used continuously. The internet access is lost ! This is definitely very very weird. plwease help !