They also have Gillum up 1, which suggest that at this pollster has a noticeable R house effect. More good news for Nelson.
They see an electorate 7% more Republican than the 2016 one.
If the Florida electorate is 7 % more Republican than in 2016, when the Republicans won Florida both in the presidential level (by almost 2 percentage points) and in the senatorial level with Marco Rubio (by 8 percentage points), then it's actually good news for the Republicans because with an electorate that is almost 10 % more Republican in Florida it increases Rick Scott's chances of victory there.
Or, the more likely answer, the poll completely oversampled Rs, and this is not representative of the actual electorate at all.
Another good takeaway is that Nelson and Gillum are still up in such a skewed sample, which is the best news that Ds could have gotten for the race.