I have similar issue with other model hikvision, see my post with variants I tried. Dropped to lowest res also to no avail and used all tags - proxy tunnel audio off on cam and gateway - works great on vlc but same error on alexa.

[Liaquat]

Re: Hikvision DS-2CD2042WD-I

[chazzzzz]

Thank you. Just started trying tags but saw that doesn’t help. The configuration on my spot is just using the RTSP per monocle directions. Works on the spot. Not on the 8. Not happy. Wanted the 8 for bigger view like the spot. Thought it would work the same. No such luck.