I'm using cdc comunication with USB stack 4.1.1 and I have problems if the string I wnat to send is smaller or equal to the In Endpoint size.
If my string is longer everything is ok.
If my string is equal never is sent.
If my string is shorter it's sent 3 or 4 times and after I never can send anything more.
At the moment I've made a workarround and if the string length is les than endpoint size I complete it with 0x00. And this way it works perfect. But this is not a solution. On the other side of the cominication I should throw away those 0x00 and maybe some of them could be part of my message.