As mentioned earlier, Unity decided to not fix this issue:
At the moment, the only workaround is to set the display scaling in Windows to 100%
guys i have a wikitude version which orks fine with unity
I meet the same problem just now. But luckily, when I delete the default Main Camera provided by Unity, Wikitude Camera starts to display on Game Panel.
Issue is present on both Unity 2018.3.6f1 & Unity 2018.3.11f1 (latest) however I can only seem to reproduce this on my laptop, as everything works fine on my PC.
I have tried both internal and external webcams but the issue is still the same. The steps I took were switching platform to android, removing the Main Camera, adding in the WikitudeCamera, changing he webcam to my external webcam and finally playing live preview.