Multi-fund AR Accounting generates incorrect receivable accounting for corresponding tax lines

Summary:

We generate all billing transactions from project billing module and there is a need to split receivable accounts based on expenditure categories. So firstly, I have enabled "Multi-fund AR Accounting" functionality and thereafter I created an accounting rule for natural account segment using a custom formula using substring and transaction line description attribute to achieve this requirement. The system is generating the receivable accounting for receivable lines as per the custom formula. However, the receivable portion derived from the tax line is not picking the correct receivable account but instead it is picking up a wash off account I have