Hi, today I made an interesting observation: while testing the upcoming MIOS Filebrowser on a MBHP_CORE_STM32, I noticed sporadical hang-ups after 100..200k of transmitted data under MacOS. Once this happened, the core behaved very similar as if it would hang-up under Windows when multiple USB MIDI ports are enabled. So, finally I had a nice test scenario to investigate this issue on a *real* operating system ;) It turned out, that transfers are working very stable (no hang-up a