The reason kicad even tries to connect to github is because your footprint libs are setup to use on demand online libs. This means kicad downloads footprint libs everytime it needs a footprint. (There is no local cache that survives closing kicad.)
This has never been a good idea. (No user control over when updates happen. Unnecessary use of data as there is no caching. Hard to maintain as every lib was required to have its own repo. The plugin dependents on the github api.)
Version 5 libs are not served this way.
I would suggest you setup kicad to use local libs. This will mean you need to download the libs and setup kicad to use the local version. More details about how this can be done is found here: How can i install a specific version of the footprint library?