I would recommend using the security debugger. As an admin go to System Diagnostics > Session Debug > Debug Security. After you click that, impersonate one of the users with your customized role, and go to the form view again. At the bottom you will see exactly which ACL is causing you to not see those fields.

My guess is that one of the following things is wrong:

1. There is a more exact ACL on the fields denying access. For that you will have to create a more specific ACL, possibly at the field level.

2. Your form layout or view is not working properly. unlikely, but possible.

I noticed there are already ACLs setup for specific fields on that table granting read access to sn_si.read role. Why not just make sn_si.read role a child role of your custom role and then they will all get the role they need?