DID ION: Adding/Updating ION services/keys does not work when using Microsoft Endpoints

**Bug severity**
3

**Describe the bug**
Adding/Updating ION services/keys does not get propagated on chain when using Microsoft Endpoints. Needs more investigation. Microsoft gives back a 200 response for them, but it never ends up in the DID Document.

**To Reproduce**
Steps to reproduce the behaviour:
1. Create an ION DID
2. Wait at least 30 minutes as ION does not allow multiple updates to the same DID in its anchoring timeframe
3. Go to https://identity.foundation/ion/explorer/ to check the DID Document was anchored
4. Update the ION DID by adding/removing services or keys
5. Wait another 30 minutes.
6. Go to https://identity.foundation/ion/explorer/ to see whether the DID Document was updated

**Observed behaviour**
The DID document stays the same, no matter whether you use short or long-form ION DIDs

**Expected behaviour**
The updated/deleted service or key to be present in the DID Document

**Details**
NA

**Additional context**
Needs checking against a local ION Sidetree implementation to see whether this is a bug in MS' implementation or in the Veramo ION Plugin.

ION support was added in issue https://github.com/uport-project/veramo/issues/336 with PR https://github.com/uport-project/veramo/pull/987

**Versions (please complete the following information):**
- Veramo: 4.x