Credit Memo not crediting the tax line

Hi Gurus,

We are facing issues with Credit Memo's.

We have upgraded from R12.0.6 to R12.2.4. Along with the upgrade, we are migrating to use the Vertex O series for the AR Tax calculation. We used Vertex Q series for AR with R12.0.6.

When we create Credit Memo on an Invoice that was created before the upgrade(R12.0.6 and Q Series), we see that the credit memo is getting created but when we complete the transaction, we see that the tax amount on the Invoice is not credited.

With the Q series, we see that for each Invoice Line there are 3 Tax lines (STATE, CITY and COUNTY). With the O series, we see that each Invoice line has only 1 tax line. The amounts on the Invoice and the Credit Memo do match.