Well the good news is that I have found an incantation that works.
Removing the sleep time did not help. Changing the time from one second down to a milisec did not work. I tried different sleeps at one second increases from the millisec. At 0.5 seconds it works. 0.4 or 0.6 it does not. I'll see if removing the sleep and hardware flow control work.
73,
Alan - W6ARH