Request for Help: CodeIgniter 3 to 4 Migration

I have tried to migrate to Codeigniter v4.
The following options at the menu are working
https://niph.org.kh/niph2025/laboratory
https://niph.org.kh/niph2025/niph-school

But I can't find out why these are not 
https://niph.org.kh/niph2025/research
https://niph.org.kh/niph2025/library
This is the original website https://niph.org.kh/niph/
I tried not to change the classes and the structure to make the migration easier
they should look like this  https://niph.org.kh/niph/home/index.html
Thanks in advance