An Internet problem

When I try to install macOS Big Sur I get the error that an internet connection is required. I have a AsRock B450 pro4 motherboard and use the RealtekRTL8111.kext. I know that the 2.3.0 Version of this kext is sometimes the reason for the internet problem. So I have tried the 2.2.2 and 2.2.1 Versions but without success. I hope somebody can help me. Amd ryzen 2700x Radeon rx460