Incorrect height of the IFrame of the email body from Jira

[Bockser]

Steps to reproduce

1. Login to Nextcloud server
2. Go to Mail App
3. Open incoming mail
4. Find and open mail from Jira (Self-Hosted)

Expected behavior

I'm expecting to see messages

Actual behavior

The emails from Jira always have a height of 8px, making it impossible to read the email

Mail app version

3.4.1

Mailserver or service

Mailcow-dockerized

Operating system

Ubuntu

PHP engine version

PHP 8.2

Web server

Apache (supported)

Database

PostgreSQL

Additional info

No response