Yes, this has been happening for ages, but lately there's been an increase. It's not always good, since I had a single machine gun that slipped inside an enclosed chamber (with no walls), and it got stuck there until it was able to break down a level 11 wall, which took ages.
It happens mostly when attacking troops are close to a gate which opens to let enemy defenders out.
Wow, your video suggests that the attacking troops do not think there is a wall there at all, which must be something different from what I'm talking about up above (I typed that in, and then watched the video, sorry). I wonder if this has something to do with the virtual debt (
https://forum.nexonm.com/forum/nexo...wn-issues/597215-virtual-debts-in-dominations) thread where someone accidentally upgraded walls for cheaper than full price, and CS downgraded the wall. It certainly must have something to do with the latest update though, since it's been happening more frequently since.