Early sent frames are lost

After device reset, with ACD disabled, the first gratitious ARP is lost. Also, the first LLDP frame is lost. Both frames are sent rapidly after the network subsystem is started.

Both frames are passed to the XC, but the XC never puts them on the line.
If you halt the ARM for a very short time in the send path, frames are send properly.
Apparently, this is a race between the ARM and the XC starting.