Hi Vittoriodale, welcome to RStudio Community.
It's hard for us to help since we cannot reproduce your data. To facilitate this, you need to provide a repr oducible ex ample (or reprex for short). You can learn how to make one by following this guide.
A minimal reproducible example consists of the following items:
A minimal dataset, necessary to reproduce the issue
The minimal runnable code necessary to reproduce the issue, which can be run
on the given dataset, and including the necessary information on the used packages.
Let's quickly go over each one of these with examples:
Minimal Dataset (Sample Data)
You need to provide a data frame that is small enough to be (reasonably) pasted on a post, but big enough to reproduce your issue.
Let's say, as an example, that you are working with the iris data frame
head(iris)
#> Sepal.Length Sepal.Width Petal.Length Petal.Width Species
#> 1 5.1 3.5 1.4 0.…