How can I ingest data from Apache Avro into the Azure Data Explorer?

for several days I’m trying to ingest Apache Avro formatted data from a blob storage into the Azure Data Explorer.

I’m able to reference the toplevel JSON-keys like $.Body (see red underlined example in the screenshot below), but when it goes to the nested JSON-keys, Azure fails to parse them properly and displays nothing (as seen in the green column: I would expect $.Body.entityId to reference the key "entityId" inside the Body-JSON).

Many thanks in advance for any help!

Here is a screenshot of the azure data explorer web interface

Edit 1

I already tried to increase the "Nested Levels" Option to 2, but all I got is this error message with no further details. The error message won’t even disappear when I decrease the Level back to 1. I have to cancel and start the process all over agein.

I just recognize that the auto-generated columns have some strange types. Seems like they add up to the type string… This seems a little odd to me either.

Edit 2

Here is some kql-Code.

This is the schema of my input .avro file, what I get from my Eventhub-Capture:

{
  SequenceNumber: ...,
  Offset: ...,
  EnqueuedTimeUTC: ...,
  SystemProperties: ...,
  Properties: ...,
  Body: {
    entityId: ...,
    eventTime: ...,
    messageId: ...,
    data: ...
  }
}, ...

And with these ingestion commands I can’t reference the inner JSON-keys. The toplevel keys work perfectly fine.

// Create table command
////////////////////////////////////////////////////////////
.create table ['test_table']  (['Body']:dynamic, ['entityId']:string)

// Create mapping command
////////////////////////////////////////////////////////////
.create table ['test_table'] ingestion apacheavro mapping 'test_table_mapping' '[{"column":"Body", "Properties":{"Path":"$.Body"}},{"column":"entityId", "Properties":{"Path":"$.Body.entityId"}}]'

// Ingest data into table command
///////////////////////////////////////////////////////////
.ingest async into table ['test_table'] (h'[SAS URL]') with (format='apacheavro',ingestionMappingReference='test_table_mapping',ingestionMappingType='apacheavro',tags="['503a2cfb-5b81-4c07-8658-639009870862']")

I would love to ingest the inner data fields on separate columns, instead of building any workaround with update policies.