[BUG] Content gets duplicated when minimizing and restoring the onboarding UI window

[kryptonit1]

Describe the bug
When you minimize the onboarding UI window and restore it the content gets duplicated.

To Reproduce
Steps to reproduce the behavior:

1. Launch IBM Notifier with -type onboarding and this JSON:

{
    "pages":[
        {
            "title":"IT Support",
            "subtitle":"IT Support can be contacted through the following channels",
            "topIcon":"https://www.nicepng.com/png/detail/242-2426263_technical-support-tech-support-tech-support-icon.png",
            "accessoryViews":[
                                [
                                    {
                                        "type":"html",
                                        "payload":"<table style=\"width:100%;background:#ffffff;border:1px solid #000;font-family:Helvetica;font-size:14px;\"><tr style=\"background:#E6E6E6;\"><td style=\"padding: 10px;\"><b>E-mail</b></td><td style=\"padding: 10px;\">itsupport@randomcompany.com</td></tr><tr><td style=\"padding: 10px;\"><b>Phone</b></td><td style=\"padding: 10px;\">040-040123</b></td><tr style=\"background:#E6E6E6;\"><td style=\"padding: 10px;\"><b>On Site</b></td><td style=\"padding: 10px;\">Visit <a href=\"https://www.google.com\"><b>Google</b></a> for more information</tr></table>"
                                    }
                                ]
                            ]
        }
    ]
}

2. Minimize the window and the restore/open the window again.

Expected behavior
The content of the onboarding UI window should be the same as before the window was minimized.

Screenshots
Before the onboarding UI window was minimized:

After the onboarding UI window was minimized and restored/opened:

Desktop (please complete the following information):

• OS: macOS 12.5.1
• Project version: 2.8.0

Additional context
N/A