Can you repro these on a brand new install of 1.10.2? How about 1.10.1?
[nodebb-plugin-mixcloud] MixCloud Embedding
On a roll.
npm install nodebb-plugin-mixcloud
Paste the URL to the mixcloud track you wish to embed.
Mixcloud allow for various types of widget, I have gone with the dark, a light is available. But it didn't suit my purpose, feel free to fork my plugin and change the iFrame Code to match what you want.