Thank you for the additional information jheiler, it matches what we have seen from our logs.
More details about the continued FDSN issue can be found here: FDSNWS Data Access Issues
To summarize, the data access issues only affect recent EHZ data (from Nov.1st onwards), that is why it was missing from your query (which included only EHE and EHN channels). While it is temporarily not retrievable, no data is being lost.