I have similar (but a little different) situation and I wanted to mention it here before I open a new issue.
When There is a missed call, I have a notification form the Fossify Phone app. Which until now is good and nothing is wrong.
But once I click the notification, it opens the calls log in system Phone app (Samsung A54), although the Fossify Phone app is the default app.

@abdo2048 No need to create the new issue, it's related to this feature request. Currently, missed call notifications are handled by the system, and it should open Fossify Phone if it's the default app. However, some OS' enforces using their apps, so things like this can happen.

@abdo2048 when you tap the notification the system dialer opens, simply because notifications are currently managed by the system. The current implementation of the notification system is inspired by another app called Koler, in fact they have the same problem. You need to delete the current implementation and go back to the solution above, or rewrite it. This is the only solution.

@abdo2048 No need to create the new issue, it's related to this feature request. Currently, missed call notifications are handled by the system, and it should open Fossify Phone if it's the default app. However, some OS' enforces using their apps, so things like this can happen.

Help me with this issue please, some contacts wont show the name in missed call notification even tho all of them are saved in Fossify Contacts allowed to be seen by other apps ”phone storage”. Also checked the box to show private contacts just in case.

@Daniel-RO-TM I think you need to update the app to the current latest version as I'm typing now (1.2.0). I think your problem will be solved by that update.
https://github.com/FossifyOrg/Phone/releases

@abdo2048 No need to create the new issue, it's related to this feature request. Currently, missed call notifications are handled by the system, and it should open Fossify Phone if it's the default app. However, some OS' enforces using their apps, so things like this can happen.

On my previous phone (without Fossify phone&contacts apps) i was using this nice ”do not disturb” app which allows you to allow ”unknown numbers” to ring while silencing contacts. On the present phone i use Fossify Phone and Contacts apps and the same ”DnD” app. Now, those contacts that dont let a name in notification if missing a call just the number, also ring as if they are unknown numbers but SHOWING the caller name. Its frustrating..how can it ring if the caller name is shown... any explanation? Somehow they are both contacts and unknown at the same time