Thanks for letting us know, we are aware of some issues importing VirtualDJ XML files and I've subscribed you to the ideas so you'll be kept updated:

https://support.mixo.dj/t/virtual-dj-cues-not-importing

https://support.mixo.dj/t/error-when-importing-virtualdj-8-xml-file

Also please make sure to update the app to the latest version 0.9.0, which can be downloaded in-app or by downloading from the beta page:

https://beta.mixo.dj/