The beta versions are not tested so it is highly likely that there are bugs in them. They are not meant for daily use and the application even says it when it is started the first time. The beta works without the license too so it is not required to buy the license if you just want to try it.
Anyway, I tried to reproduce the problem by changing my timezone to Tokyo Standard Time, matching the clock in the Toodledo's settings and the task was shown correctly in Rainlendar. So something is configured differently in your system if you the times are not the same. I would need to get the Rainlendar's debug log
to know where things go wrong.