Puzzle with incorrect solution

Played puzzle streak this morning, and my first puzzle was the following position:

r1b1kb1r/ppp1n2p/2np1p2/3N4/2B1P3/5N2/PPP2PPP/R3K2R w KQkq - 0 1

The puzzle info says it was taken from 5 + 0 blitz game ItsAllMurloc (1629) v adnan_inan (1673)

I played Nxc7+, which was flagged as incorrect, and it showed Nxf6# as the “correct” answer.

Of course, since Black can respond with Kd8, this isn’t mate.

I’m hoping this is the appropriate way to report such an issue. If I’ve overlooked an option on the site where I should report this, please let me know, but I searched the menus and checked the FAQ and could not find such an option. Thanks!

I assume you're talking about this puzzle: lichess.org/training/BtB63

Black can't respond with Kd8 because that square is occupied by a black queen, so it is a checkmate. Perhaps somehow that queen failed to render on your board? Do you see it now?

That is the correct puzzle, and you’re right, there must have been a rendering issue. I even took a screen capture because I didn’t trust my eyes and brain, but the d8 square was definitely unoccupied. When I execute the puzzle now, I see the queen. I’ve never experienced such an issue before (at least not that I noticed).

FYI, in case it’s helpful, I’m using DuckDuckGo 7.64.6.1 on an iPad Pro 3rd Gen running iPadOS 14.7.1.

Thanks for your prompt reply, ProgramFOX!