The answer to your question is laid out here:
- Dimensional regularization vs methods in fixed dimension with and without $\gamma_5$
- $\gamma_5$ algebra ambiguities in Feynman amplitudes: momentum routing invariance and anomalies in D=4 and D=2
I have a question though: given that you sound privy to the essence of the issue, do you happen to be the author of one of the above papers?