A sibilling comment was explaining it: basically your ublock (that I use too) is regularly blocking the request to google analytics everywhere, github code doesn't fail in that case, but since the repo contained the "googleanalytics" substring ublock was blocking the request (because it checks for words in the urls that get requested) to the github server thus making the starring function fail.

Other repo do not have "suspicious" strings in their url, so they pass through ublock, while the real google analytics call is blocked and github does not fail. You can check the network tab in the developer tools in chrome around github and see that calls to GA gets blocked and calls to github pass while on that specific page also the call to github fails