isRepeatable: true groups not rendering in Modeler v5.36.1 on macOS

I’m facing a very strange issue where the isRepeatable: true property for groups in element templates is not rendering the + Add button in the properties panel. I have exhausted all standard and advanced troubleshooting steps and the issue persists, which points to a very specific environmental problem.

Even with the most minimal template, the isRepeatable functionality does not render in the UI. Here is a screenshot of the result using the minimal test template:

And here is the json template:
{
“$schema”: “https://unpkg.com/@camunda/zeebe-element-templates-json-schema/resources/schema.json”,
“name”: “Minimal Repeater Test”,
“id”: “io.camunda.connector.minimal.repeater.v1”,
“description”: “A minimal test for the isRepeatable feature.”,
“appliesTo”: [
“bpmn:IntermediateThrowEvent”
],
“elementType”: {
“value”: “bpmn:IntermediateThrowEvent”
},
“groups”: [
{
“id”: “minimalGroup”,
“label”: “Test Repeater Group”,
“isRepeatable”: true // the problem
}
],
“properties”: [
{
“type”: “String”,
“label”: “Test Field”,
“id”: “testField”,
“group”: “minimalGroup”,
“binding”: {
“type”: “zeebe:property”,
“name”: “testField”
}
}
]
}

Any ideas on what could be causing this or what to check next would be greatly appreciated. Thank you!