UBE Report does not return result for first few runs after object deployment

Hi! We are on 9.2 Tools 9.2.3.1. Oracle DB 12.2, WebLogic 12.2 as JAS. All host OS are Windows Server 2016.

One of our developers encountered an issue. She created a custom report with a custom view that Left Outer Join F0901 and F0902 . She found that every time she revised and deploy the UBE object, the first few times (about 3-4 times) running of the report returns nothing or zero figures. Then when, say, the 5th time, it resumes normal. The results are correct (according to her). We are not sure why. JAS server log, Enterprise Server kernel log and UBE jde.log do not show any error. jdedebug log is too large to look for issue. Any hint on what should we look at? How to troubleshoot? Any know issue on Left Outer Join?