Confirmed its a bug. I know what happened, and currently being fixed.
sendsmsd_queue
value in config.php
limiting the number of queue that can be processed at one time. But since your 10 other queues were scheduled for later then the 11th queue and the next will not be processed until the earlier 10 scheduled SMS sent.
See this:
Those queue are sorted latest on the top. The first on the top wont get sent at 20.45 if the other 10 at the bottom processed/sent. It will be sent around 21.00 soon after the other 10 sent.
temporary solution
edit
config.php
, setsendsmsd_queue
to0
and restartplaysmsd
anton