I think I found the root cause of the problem.
My strategy has "Bar Closing" as opening point of the Position.
I synced my computer time to make sure it's accurate.
If I leave "Bar Closing time advance in seconds" as default 3 seconds, I get "a bar close event" every minute on a 1 minutes chart in Journal section (system message turned on). It shows most bars close 2 seconds early. very few 3 seconds or 1 second early.
However, if I change the parameter to 1, I don't always see bar close event. Instead, I sometimes see "a secondary bar closing event", but not guaranteed. i.e. occasionally, there is no "bar close" or "secondary bar close" at all for that minute! In this case, even all conditions in opening logic slots are met, NO action will be taken in FST because there is no bar close event.
To sum up,
1, computer time must be accurate. I would use some tool apps to force time synced every hour. I think so-called "Bar Closing time advance in seconds" calculation is base on local computer's time.
2, the parameter in "Bar Closing time advance in seconds" should be adjusted according to the broker until "bar close event" is shown every minutes on 1 minute chart. Each broker may have slightly different timing on server.
3, this scenario may only apply to timing related issue, not issues caused by other factors, e.g indicators etc.