Commento import results in a tree which refuses to be represented

[RealOrangeOne]

I've imported following the commento docs, and after some manual URL updating (I'll open a PR soon), the content imports. However, the tree it creates doesn't appear to be valid, and can't be represented by the API:

{
	"comments": [],
	"info": {
		"url": "https://example.com/page/",
		"count": 5,
		"first_time": "2023-11-01T22:24:04.639965Z",
		"last_time": "2023-11-01T22:24:04.639965Z"
	}
}

Notably, if I change &format=tree to &format=plain, all comments are shown as expected, and a comment's pid matches another id, with root comments having a pid of "root". Example:

		{
			"id": "6d3bb64ff73b5f9d6a959212ffde472a51abf8bdefaa5ed843659796bceef9de",
			"pid": "46baf36433830a4e8bda1de56290cf5fd74c08bfa844fee4ec1744985dc77010",
			"text": "other comment text",
			"user": {
				"name": "xxxxxxxxxxx",
				"id": "commento_xxxxxx",
				"picture": "undefined",
				"ip": "xxxxxxx",
				"admin": false
			},
			"locator": {
				"site": "mysite",
				"url": "https://example.com/mypage"
			},
			"score": 0,
			"vote": 0,
			"time": "2023-11-01T22:23:47.112062Z",
			"imported": true,
			"title": "page title"
		},
		{
			"id": "46baf36433830a4e8bda1de56290cf5fd74c08bfa844fee4ec1744985dc77010",
			"pid": "root",
			"text": "Comment text",
			"user": {
				"name": "Name 1",
				"id": "commento_xxxxxxxxxx",
				"picture": "xxxxxxx",
				"ip": "xxxxxxxxxxxxx",
				"admin": false
			},
			"locator": {
				"site": "mysite",
				"url": "https://example.com/mypage"
			},
			"score": 0,
			"vote": 0,
			"time": "2023-10-31T11:03:25.403282Z",
			"imported": true,
			"title": "Page title"
		},

The content is clearly there, as the count value is definitely correct - however it seems there's an issue when representing it as a tree

[paskal]

Could you please attach the export of the comments which can be used to reproduce the issue? You could redact all confidential information from it.

[RealOrangeOne]

Of course: remark-1696.json

Oh, and version remark42 v1.12.1-1f2500f-20230821T11:59:46

Redacted and not entirely representative of a usual export, but importing this into remark causes the issue. Imported with remark42 import -p commento -f ./var/data.json -s mysite.