I have found another problem.there are too many timenow process, and it seems all of them register to proximityd,but only one set interval to desired value(setting file), the other uses default interval which is 100ms.the way proximity work is that it poll based on the lowest interval process, this render the setting useless.

If you set by hand the interval for all timenow process, then it will work correctly.

You can test this: if the screen black immediately when you cover the proximity sensor,then proximityd is polling at 100ms.