Maybe they didn't like either candidate. It happens.
What are they suggesting - just assume that everyone who voted D/R for governor intended to vote D/R for Senate?
It’s simple. There was a Black man on the ballot for Governor. They went out to vote for the Black guy, the other races didn’t matter or they didn’t care.
What the media didn’t tell you in that story is that the undervote was a nearly identically split between D/R.
Desantis got 10K more votes than Scott and Gillum got 10K more votes than Nelson.
Voters typically pick a candidate for most major races, with more voters choosing not to vote in the less well known races lower down on the ballot.
The statistics of how many voters choose to skip a race are easily determined, and it is a standard test of voting system integrity to check what percentage of voters apparently did not vote in a particular race. Once we know what the real numbers are it should be possible to see if what was reported is unusual or not.
In most cases the percentage of voters who skip a race at or near the top of the ballot is small.