Behaviour initial run relating to Comment field is not working as expected in Service Project

Steps to Reproduce

1. Create a Behaviour mapped to a Service Project (using Issue Type) and a Software Project
2. Use the following script in the Initializer and Comment field server-side script:

   getFieldById("comment").setFormValue("TEST_STRING")
   getFieldById("summary").setFormValue("TEST_STRING")
   

3. Ensure that ScriptRunner's 'Service Desk Template Comments' built-in script is disabled (and/or any similar functions by other plugins)
   • Go to Jira Administration > Manage Apps > ScriptRunner > Built-in scripts > Service Desk Template Comments
4. Go to an Issue in the Software Project and edit it. Notice that both fields are populated as per the Behaviour script
   Ensure that the Comment field is visible in the Edit Screen
5. Go to an Issue in the Service Project and edit it

Expected Behaviour

Both fields are populated as per the Behaviour script, just like how it was for the Software Project

Actual Behaviour

Only the Summary field is populated. The Comment field would only be populated in the subsequent script execution (manually editing the Comment field to trigger the server-side script). If you repeat the test with only the server-side script (Initializer script removed), both fields would not be populated in the initial run.

Here's a screen recording video demonstrating the problem: Comment_Behaviour_Initial_Run_Bug.mp4
Tested in Jira 8.15.0, Jira Service Management 4.15.0, ScriptRunner 6.51.0