[BUG] Alert escalation using a case template doesn't assign classification

[xBounceIT]

Describe the bug
Im trying to merge an alert into a new case using a pre-defined case template. The template is barebone with only this definition:

{
    "name": "Template Suspicious User Activity",
    "display_name": "Template Suspicious user Activity",
    "description": "",
    "author": "",
    "title_prefix": "",
    "summary": "",
    "tags": [],
    "tasks": [],
    "note_directories": [],
    "classification": "suspicious-user-activity"
}

The classification is a custom one. My goal is to have a case with that classification assigned, mainly to be used via API.

This doesn't work, as the case get's created without classification.

To Reproduce
Steps to reproduce the behavior:

1. Create a custom case classification
2. Create a custom case template which assigns that classification
3. From an already created alert, merge it into a new case using the custom template
4. Observe the missing classification in the newly created case
5. Try to create a new case from scratch with the custom template
6. Observe the classification correctly assigned

Expected behavior
Template's classification to be assigned to escalated alerts

Screenshots
Escalated alert:

Case created from scratch:

Desktop (please complete the following information):

• OS: Windows 11 25H2
• Browser Firefox 148

Smartphone (please complete the following information):
N/A

Additional context
IRIS v2.4.27