I've included a picture of the VI that I use to write a frame, which includes XNET Clear.vi. This works for a time, but if I use this over and over in a program to write many different frames it will get to the point where it won't work anymore. I've had a similar issue with not properly closing VISA sessions, but it seems like XNET Clear.vi should take care of this. The only thing that does fix it is me closing and reopening Labview.
Also, it doesn't throw and error (I think). I only find out when the device I am testing stops responding because the write commands stop being sent.