R31804 displaying variance for WO , where no variance reported.

Hi

We are working in E9.0 and noticed few issues when we ran R31804, for one company. The WO variance report is displaying the variance amount, actually there is no such variance exists. Initially we thought the WIP accounts 3120 was not setup for that specific company and , so did setup and ran R31804. However it is still displaying the variance and makes IV entries for those variances.

Currently the variance amount is equal to the "all IM issues cost + routing hours cost + outside process OP cost" . Have verified all AAIs setups and everything looks good. The R31804 report is not showing any error message or not in WC.  Appreciate your inputs /suggestions.