Thanks for sharing the PDF form to understand the whole scenario better.
I tab out of the last field on page 1 and then have to tab 3 times to get to the first field on page 2. I have no idea where the two tabs are tabbing to.
Once you are done filling the last field of the Page-1 then you have to use 3-4 extra Tab to come to the first filed of Page-2, because the dates 2022-2023 are also text fields. So your cursor is going into 2022 and 2023 when you click Tab after filling the last field of Page-1. These are the places where extra tabs are tabbing.
*See the blue box (the form filed) around the years 2022-2023
Using the "Prepare Form" tool Adobe Acrobat DC (which is a paid product) you can check exactly how many and what type of "form fields" are there.