Two problems:
- We do not support Append-type blobs with Filebeat, each time an append occurs we will treat it as if it was a new file and process the entire file again. See my recent comment on another person's post I want to read an append-format Blob file with filebeat - #2 by strawgate
- The content-type on the content you've uploaded to Azure blob storage is incorrect and there is no way to override it in the beat. The uploader sets the content-type when they write the blob and when we read the blob we trust the content-type to be correct. We really should have an option for overriding this so ive filed an issue in the Beats repo for this. [filebeat][azure-blob-storage] Support custom content-type · Issue #42971 · elastic/beats · GitHub