The Apr 11 2019 version of T3000 software will not access the scheduler function of a Tstat8. I loaded the March 19 2019 version and I can access the scheduler function of the Tstat8.
Thanks for your efforts with the products Hully. I managed to duplicate your issue, we will push out a fix later today.
Just for reference its always a good idea to update both the T3000 front end and the device firmware which you can do from T3000 as shown below. While doing exactly this just now to duplicate your issue I noticed that we need to add the ability to do bacnet device firmware updates, working on that now.