sync_modes not populated after call to streams.get_stream_properties

When calling directly the API
```bash
curl --request GET \
--url 'https://api.airbyte.com/v1/streams?sourceId=03604837-98e**********8b8c7e4a&destinationId=d89fd9a*********6d6-85c8-ddc30e7a85ec' \
--header 'accept: application/json' \
--header 'authorization: Bearer eyJhbGciOiJSUzI1NiIsInR5cC **************FnxpQVDlmiwxee0PpoSQ'
```

it nicely returns sync_modes info:
```json
[
{
"streamName": "abandoned_checkouts",
"syncModes": [
"full_refresh_append",
"full_refresh_overwrite",
"incremental_append"
],
"defaultCursorField": [
"updated_at"
],
"sour ..."
```
However, when using the python SDK
```python
res_sp = s.streams.get_stream_properties(request=api.GetStreamPropertiesRequest(
source_id=source_id,
))
```
the sync_modes are always returned as `None` for all streams