It has become difficult to conduct polling with the advent of the cell phone, and the outrageous number of spam calls in recent years have made it even more difficult.

I don't think pollsters have been able to fix their problems from 2016. In 2018, there was one poll that had Andrew Gilliam up by 7 points right before election day (FL governor), and DeSantis ended up winning. The other polls right before election day had DeSantis down by 4-5 points.

Part of the problem is the strength of the Democrat propaganda machine and its strategy of labeling Trump supporters and Republicans as racist. This makes Republicans more likely to hide their political views, especially from strangers (pollsters). I would trust voting data regarding party affiliation more than polls, but this is infallible, for example, approximately 30% of people at Trump rallies are Democrats, and may vote for Trump.