Summary values are not updated

[denniserdmann]

Contao: 4.13.5
MP-Forms: 4.4.0

Steps to reproduce:
Backend:

1. add field on page 1
2. add summary on page 2 with ##mp_forms_debug##

Frontend:

1. go to page 1, add value, press submit to go to page 2
2. go back to page 1 and change value
3. press submit to go to page 2

Result: the value hasn't changed

[denniserdmann]

My fault. I used a hidden field with the same name on page 2 that conflicted with the update process.