How to change default balancing segment in tax journal

When we create a manual tax journal and press the 'Tax' button to calculate the tax lines, the tax liability code it generates is using the balancing segment of the original expense line. The same tax liability code should be used for all expense lines regardless of the balancing segment.

For example our tax liability account is 0866.31 (31 is the balancing segment).

If we create a manual tax journal against revenue account 3003.31 for $110 with 10% tax, then $10 should go against 0866.31 - correct, this works. However, if we create the same manual tax journal against revenue account 3003.41 (balancing segment is now 41), then $10 should also go against 0866.31 but instead, the 'calculate tax' function is trying to create the tax line against 0866.41, which doesn't exist.