Yes! This happened to me years ago outside Bristol, around 2 in the morning. Metallic taste, almost like sucking on a old coin, and then about 90 minutes just... gone. Came round sitting on a wall with no memory of how I got there.
I've spoken to a few people in the mediumship community who reckon the taste could be electromagnetic in nature, like your body is responding to something in the environment before your conscious mind even registers it. Not sure I fully buy that explanation but it's the best I've heard so far.
Anyone else notice other physical sensations alongside it? I had a sort of pressure behind my eyes too, almost like the start of a migraine but it never became one. Would be interesting to see if there's a pattern across different accounts.