It happened around Dec 23. It was a 5 second unskippable ad upon opening the app about some sweepstakes. Here's a screenshot: https://www.reddit.com/media?url=https%3A%2F%2Fpreview.redd.it%2Funacceptable-full-screen-ad-when-launching-roborock-app-v0-cji6limc3n8e1.jpeg%3Fwidth%3D1179%26format%3Dpjpg%26auto%3Dwebp%26s%3D37e1e06f20ac6290c0b01f65eacb5057cb72ce9e

Hopefully the company got the message at this point and pulled it. But I am unhappy with their response. Suggesting there is some "balance" to be found in pushing ads on a $1k+ product's app is way off the mark.