Problems synchronizing tasks between Apple devices

I'm having problems synchronizing tasks between Apple devices. It sometimes takes a very long time for the lists on the devices to be identical again.

I am using GoodTask on my MacBook, iPhone, and iPad.
I always use the latest app and operating system versions (but I haven't updated to 16.8 on all three devices yet).
I also synchronize tasks that come from Microsoft Exchange/ToDo.

Thanks for using GoodTask.

Would you open Reminders app and check if it’s syncing properly? As you know, GoodTask uses data from Reminders app and relies on its sync mechanism.

For settings, iCloud Drive is used to sync the preferences data.

Thanks!

Is the manually created sequence of tasks not synchronized?

If not, that would be an urgent wish from me

In fact, it looks like I have to open the Reminder app on the iPad and iPhone for the synchronization to work. Can that be? Can it be changed?

Not sure what you mean exactly but you don't need to open Reminders app for data to get synced. It should be done by itself.

But from time to time, OS gets stuck and opening Reminders app or restarting the device fixes the issue.

Thanks!