I will need a few more info to get more insight on the issue.
- Can you please let me know what payment option / plugin are you using?
- Do you set a fixed commission from options in the wp-admin ? or is it set dynamically by the code/plugin?
- Will it be possible for you to test the issue on a staging/test site with minimal setup/plugins with a default them and see if the issue is replicated there or not?
Sorry for keeping you waiting. We encountered a problem on the test site. We are talking to a different plugin author to fix this. We'll let you know when they fix the issue.