Sorting by name does not work properly in Phone and Contacts apps

[antodc]

Checklist

• I can reproduce the bug with the latest versions.
• I made sure that there are no existing issues - open or closed - to which I could contribute my information.
• I made sure that there are no existing discussions - open or closed - to which I could contribute my information.
• I have read the FAQs inside the app (Menu -> About -> FAQs), in the README and my problem isn't listed.
• I have taken the time to fill in all the required details. I understand that the bug report may get dismissed otherwise.
• This issue contains only one bug.

Affected Android/Custom ROM version

Android 11

Affected device model

Oscal C60

How did you install the apps?

F-Droid / IzzyOnDroid

Which apps are affected?

Phone, Contacts

Steps to reproduce the bug

1 Create a new "Contact 1" like
Name: Aaa
Last name: Ddd

2 Create a new "Contact 2" like:
Name: Aaa
Last name: Bbb
Prefix: Ccc

3 Sort by name

Expected behavior

Contact 2 is shown before Contact 1, because they have the same name and the last name Bbb should come before the last name Ddd.

Actual behavior

Contact 1 is shown before Contact 2.

Screenshots/Screen recordings

Additional information

If you remove the prefix in Contact 2, then the two contacts are sorted properly. My impression is that Fossify Contacts first compares the first names, then the prefixes. It then sorts the "null" prefix before "Ccc". I would expect that Name and LastName are compared before any other field.

No response