From 2018-06-05 09:00:00
To 2018-06-05 18:00:00
Security Type Crypto
Market GDAX
Resolution Minute
Status Resolved

Corrupted Files Missing Files Listing/Delisting Error Dividend Error Missing Points Wrong Values Split Error Name Mapping Error TickerBCHUSDFrom2018-06-05 09:00:00To2018-06-05 18:00:00Security TypeCryptoMarketGDAXResolutionMinuteStatusWaiting Review

The issue is actually with Bitfinex data, not Coinbase:
Bid prices at around 11 and 14 are zero.

Other dates:
2018-08-31T15:24:00Z ETHUSD -1
2018-08-31T15:55:00Z LTCUSD -1