Empty "Extension domain" on BioCompute Object Builder page

**Describe the bug**
All our GlyGen BCOs are created with extension domains, but when I open any of our BCOs the extension domain is empty on the editing page but is present in the "Raw JSON View". Cyrus and I have tried this with several BCOs and still get the same result.

**To Reproduce**
Steps to reproduce the behaviour:
1. Go to 'https://biocomputeobject.org/builder?https://biocomputeobject.org/GLY_000001/DRAFT'
2. Click on 'Raw JSON View' in the left hand menu, and the extension domain object is there with our dataset categories.
3. Click on 'Extension Domain' in the left hand menu.
4. See error - the domain page is empty.

**Expected behavior**
To see the extensions in the "Raw JSON view" also on the 'Extension Domain' page.

**Screenshots**
The extension domain object in the 'Raw JSON View':
The corresponding 'Extension Domain' editing page is empty:

**Desktop (please complete the following information):**
- OS: Windows
- Browser: Microsoft Edge
- Version: 127.0.2651.105