This article summarises a potential cause of performance issues when loading into the sim.
One of our testers found that when loading into the sim, nothing was loading up, and the EFB was also non-responsive.
We found the solution to the issue was that the tester was running MSFS as administrator. When running MSFS as administrator, and not the Fenix app as administrator, the MSFS program didnt recognise Fenix and wouldn't allow hook in.
Once the tester opened both under admin, Fenix successfully hooked into to MSFS.