Dynamic xpaths not working with HTML task preannotation via flask ML backend

**Describe the bug**
“XPath-based predictions are added to the task data but not visually displayed in the UI when using dynamic XPaths like .//p[contains(., 'Nutzenbewertung')].”

**To Reproduce**
Steps to reproduce the behavior:
Use the following HTML in a Label Studio project:
html

Nutzenbewertung gemäß § 35a SGB V

Another paragraph containing Nutzenbewertung.

Add predictions using the XPath:

//*[contains(text(), 'Nutzenbewertung,')]
Observe that the prediction is added to the task data but not displayed in the UI.

**Expected behavior**
“The prediction should be visually displayed in the UI, as the XPath matches the correct text nodes.”

**Environment (please complete the following information):**
- OS: macOS Sonoma
- Label Studio Version v1.15.0

**Additional context**
The XPath works in a flask backend and in a browser (showing the html or the html within Label studio) but not in Label Studio.
Predictions using exact XPaths derived from annotations made in the label Studio interface like /p[34]/text()[1] work when put statically in the flask backend, but dynamic XPaths fail.

Task source with prediction and annotation (annotation done after prediction, so I am sure I could not see the prediction even before the annotation):

{
"id": 5084,
"data": {
"html": "

Nutzenbewertung gemäß § 35a SGB V

\n

Another paragraph containing Nutzenbewertung.

"
},
"annotations": [
{
"id": 1306,
"result": [
{
"id": "735b0e8f-2c80-4168-b358-6662097a7739",
"type": "labels",
"value": {
"end": ".//p[contains(., 'Nutzenbewertung')]",
"text": "Nutzenbewertung gemäß § 35a SGB V",
"start": ".//p[contains(., 'Nutzenbewertung')]",
"labels": [
"Ursprungsprojekt"
],
"endOffset": 33,
"startOffset": 0
},
"origin": "prediction",
"to_name": "text",
"from_name": "Was war der ursprüngliche Auftrag?"
},
{
"id": "Wtcf3gI9g7",
"type": "labels",
"value": {
"end": "/p[1]/text()[1]",
"text": "Nutzenbewertung gemäß § 35a SGB V",
"start": "/p[1]/text()[1]",
"labels": [
"Ursprungsprojekt"
],
"endOffset": 33,
"startOffset": 0,
"globalOffsets": {
"end": 33,
"start": 0
}
},
"origin": "manual",
"to_name": "text",
"from_name": "Was war der ursprüngliche Auftrag?"
}
],
"created_username": " XXXXX, 1",
"created_ago": "0 minutes",
"completed_by": {
"id": 1,
"first_name": "",
"last_name": "",
"avatar": null,
"email": "XXXXX@XXXXX.com",
"initials": "ch"
},
"was_cancelled": false,
"ground_truth": false,
"created_at": "2025-01-17T15:32:22.888219Z",
"updated_at": "2025-01-17T15:32:22.888240Z",
"draft_created_at": "2025-01-17T15:32:09.385624Z",
"lead_time": 27.26,
"import_id": null,
"last_action": null,
"task": 5084,
"project": 1,
"updated_by": 1,
"parent_prediction": 175,
"parent_annotation": null,
"last_created_by": null
}
],
"predictions": [
{
"id": 175,
"result": [
{
"id": "735b0e8f-2c80-4168-b358-6662097a7739",
"type": "labels",
"value": {
"end": ".//p[contains(., 'Nutzenbewertung')]",
"text": "Nutzenbewertung gemäß § 35a SGB V",
"start": ".//p[contains(., 'Nutzenbewertung')]",
"labels": [
"Ursprungsprojekt"
],
"endOffset": 33,
"startOffset": 0
},
"origin": "prediction",
"to_name": "text",
"from_name": "Was war der ursprüngliche Auftrag?"
}
],
"model_version": "v1.0",
"created_ago": "10 minutes",
"score": 1,
"cluster": null,
"neighbors": null,
"mislabeling": 0,
"created_at": "2025-01-17T15:22:24.182589Z",
"updated_at": "2025-01-17T15:22:24.182602Z",
"model": null,
"model_run": null,
"task": 5084,
"project": 1
}
]
}

"Prediction" passing the xpath from label studio also via the backend (this shows up in the gui and is highlighted):

{
"id": 5083,
"data": {
"html": "

Nutzenbewertung gemäß § 35a SGB V

\n

Another paragraph containing Nutzenbewertung.

"
},
"annotations": [],
"predictions": [
{
"id": 174,
"result": [
{
"id": "123KBhsJdU-5w",
"type": "labels",
"value": {
"end": "/p[1]/text()[1]",
"text": "Nutzenbewertung gemäß § 35a SGB V",
"start": "/p[1]/text()[1]",
"labels": [
"Ursprungsprojekt"
],
"endOffset": 33,
"startOffset": 0
},
"origin": "prediction",
"to_name": "text",
"from_name": "Was war der ursprüngliche Auftrag?"
}
],
"model_version": "v1.0",
"created_ago": "14 minutes",
"score": 1,
"cluster": null,
"neighbors": null,
"mislabeling": 0,
"created_at": "2025-01-17T15:21:34.936985Z",
"updated_at": "2025-01-17T15:21:34.936995Z",
"model": null,
"model_run": null,
"task": 5083,
"project": 1
}
]
}