Language and notification issue after upgrade from 7.13 to 8.3

After upgrading SuiteCRM from 7.13 to 8.3 I encountered some issues regarding changing the language to Dutch and slowdown due to the notification.
When I login and set my language to Dutch, the language remains to stay in English.
If I hover over the notification icon however, I can see some parts in Dutch even though everything else is in English.

In the above image ‘Afspraak’ seemed to have remained unchanged even though everything else is in English.
In the console I noticed that the notification seems to continuously search for an image with the name ‘Afspraak’ which causes SuiteCRM to be rather slow.

I was able to fix the language from not changing to Dutch by uninstalling the old language pack and installing the latest language pack for it, but the slowdown due to the notification seemed to have stayed.
When I hover over the notification icon with the language set to Dutch, the dropdown of the notification remains unchanged and is similar to the first image above even though the language as been set to Dutch and it seems to keep searching for the same file.

I was able to fix the slowdown by making a copy of the ‘Meetings.svg’ file and renaming it into ‘Afspraak.svg’ inside the folder ‘public/dist/themes/suite8/images/modules’. This method seems to be a temporary fix if there are other notifications that happens to be similar.

Is there a way another way to fix the slowdown that would be permanent?

I wonder if it’s something in your database, in the reminders table. I know that table existed in v7, I am not sure about v8…

I couldn’t find anything that seemed out of place in the reminders table.
But after a search through the whole database for any values containing Afspraak, I did stumble upon the alerts table.
In the alerts table Afspraak was part of the value for the name column and it is the value for the target_module column.
So, thank you for making that suggestion.

I had to rename Afspraak to Meetings in both columns for it to appear properly under the notification dropdown.
Only changing it in the target_module column gave the results below.
The former is when the language is set to English and the latter is set to Dutch.

The following questions then pops up:

  1. What file(s) made those inserts?
  2. Why Afspraak instead of Meetings?