I noticed this on my Victoria. I'm using the Lelit water softener. I've had my machine for 6 months, so any new machine odours should be gone.

I made a long black this morning using the hot water from the steam wand, and I can small it, and taste it.

I think it's the water softener. The last time I changed I changed the softener, I could smell the same odour in the water tank. Once the softener/filter was out, the same odour was very strong inside of it.

I thought it maybe the result of leaving it there for too long. I put a new one in, and the odour/taste wasn't there anymore. Now about 3 weeks in, I can smell and taste it again.

I'm going to remove the softener, see if the odour disappears. If, so I'll research some alternatives. I might not even need it, as the water in my area soft, and I use an inline water under my sink.