i'm using Unity 2019.2.14 with wikitude SDK 8.10.
When i build on android my app, there is no problem for tracking.
I keep left landscape orientation => good feet of my GameObject with image target.
When i change device orientation (portrait), no problem for canvas scaling => GameObject is a bit displace on image target.
I sent screens of my build on smartphone with the two orientation for better comparison.
Thank you for reporting this issue. We were able to reproduce it as well. Unfortunately, I don't have a workaround at the moment, but we'll try to fix it as soon as possible.