Missing task on To Do

I noticed that one task is missing on my Tasks and Today list. It was overdue. I am using desktop app for Macos. I logged into webpanel and I see that task list is not full too. After waiting a minute and changing lists, I started to see all my tasks, including that missing task as well. I restarted the desktop app but still missing. 

For that specific task, it is ok. I remembered. But I am worried if other tasks might be missing in the future as well.

An other thing I noticed on webpanel is that there is one weekly recurred task which I have been completing every week, is actually overdue form last 4 weeks. Somehow my completions didn't work on desktop for that specific task.