Hi @Sacha B ,
I discussed this question with the team, this behavior is a known issue, and there is no workaround yet.
If you have to use ApplicationTrigger
, it is recommended that you do not use multiple instances for the time being. If you want to get further technical support, I suggest that you might need to open a support ticket for this. Please contact our paid support at MS Support. You will get 1:1 support on that. Select Developer Tools -> Windows UWP Development -> Windows 10 Universal App Dev -> Runtime Platform -> Background tasks and transfers API in the support page and you could contact the team. Please kindly note that your support ticket will be free if it is Microsoft's issue.
Thank you
Junjie