Hi JimHuang2016
TransPost Plus uses the API rather than the import mechanism and some of our users have found that it works better for importing larger files. This is because it uses the API designed specifically for AR Live.
If you do not want to kick your users off and check out your file you might like to try it out. It as available as a free 30 day trial so you can use it to solve a one-off problem and evaluate whther it resolves your issues without any commitment.
Regards
Julia Roberts
TransPost Support
Phone: 1300 768 993
Email: support@transpost.com.au
Web: https://www.transpost.com.au