after disabling notifications, the dialog shows up, but we are stuck with an endless loop of accept share pop ups.

I tried to reproduced the fatal error. It's not showing up.
Some possible reason for this case:
1- upgrade the app
2- recent commits

The issue still presists. checking the files to find out where INotification instance is calling to find the root cause.

Finally, I reproduced the error which is irrelavant to add share federated event:

1- The error is related to notification that sciencemesh tries to send via email
[Wed May 31 22:15:49.838361 2023] [php7:notice] [pid 257] [client 172.18.0.8:49384] PHP Fatal error: Declaration of OCA\\ScienceMesh\\Notifier\\ScienceMeshNotifier::prepare(OCP\\Notification\\INotification $notification, string $languageCode): OCP\\Notification\\INotification must be compatible with OCP\\Notification\\INotifier::prepare(OCP\\Notification\\INotification $notification, $languageCode) in /var/www/html/apps/sciencemesh/lib/Notifier/ScienceMeshNotifier.php on line 72

step to reproduce it:
1- share a file from oc1/nc1 to oc2
2- add new row in oc_notification table with this query

Fix this first here and here.

Also there's still conflict between file federated app with notificaion app. Still checking to find the root cause.
Here's report for now:
in this section, it's using different structure to call the file accept popup. In notification app, I couldn't find anything like this. However, in this section it seems the notification fetched but it's always empty. I'm trying to find out where this object filled.

Find this
The notification app prevent to show the modal and notification app will add new row in the ring bell section on the header.
Checking why it's not add the row.

The notification appears on the topbar in notifcation app.

There's point that still has conflict

• It seems two times the accept/decline button called while in db the structure of the row has single value
  

• Storage Controller + methods to handlePost and handleDelete
  *** Sciencemesh share provider has complex instruction for delete/unshare a file. (working on this)

Methods are implemeneted to the StorageController
The links for accept/decline is not still working
find this as accept and this as decline. Still working on it.

I tried to send a post request based on this Accept a Pending Federated Cloud Share and Decline a Pending Federated Cloud Share documents it will return null.
The root cause of this is related to headers that send by the curl request.
Needs another way for accept/decline pending federated share in StorageController
@michielbdejong do you have any advice on this?

As I checked with MohamadReza and Mahdi, It seems the header of curl request is similar to the request that normally we send through app without notification app.

The funny thing is that when we send a curl request to HTTP_ORIGIN as POST it doesn't read the params from Header Request and it reads from Query params!
Also, externalShares endpoint always return 200 if we decline/accept without any information.