Combine PDF forms including filled-in information

I have been trying to file my taxes by filling out the individual forms, which are fillable PDFs on the IRS's website, and concatenating them using the pdfunite command:

pdfunite f1040.pdf f1040s1.pdf f1040s3.pdf f1040sa.pdf Fed_2022_all.pdf

However, that results in the saved form values from each form being saved only on the first page. For instance, Form 1040 is two pages, and the form fields on page 2 are rendered uneditable. How can I prevent this?