I first noticed during the 2008 Democrat primaries that it took forever to count the last 5% of the vote. I didn’t connect the dots at the time because I thought the insiders wanted Hillary to win. In retrospect, the fix was in for Obama. It doesn’t take a week to count the last 5% of the vote.
Same with Bernie in the 2016 CA primary. Dominion Systems in the Bay Area counties came to the rescue late at night.