Errors decoding firehose

When subscribed to the firehose (tested on https://katproto.girlonthemoon.xyz/) I occasionally get decode errors:
Warning: Websocket error: Decode error: Failed to deserialize DAG-CBOR: Mismatch { expect_major: 6, byte: 246 }

The error seems to occour in serde_ipld_dagcbor (looks like it probably comes from here)

Issue seems to occour on record deletions, where cid is null.