How do you determine that the endpoint halts?
Does this happen only on a specific PC? Which USB3 host controller does the PC have?
We have not seen such an issue in our tests.
Do you get a similar issue if you try streaming with UsbBulkSrcSink firmware?
The problem seems to be related to the flags. If I remove the flag checks in the vhdl (aka. it just writes, also if the buffers are swapped), it works flawlessly. But of course, there is a data loss, because it still writes while the buffers are swapped. Any idea what the problem might be?