how to correct code of plugin?

Hi experts,

I created two plugins (create,update) on "opportunityproduct" entity on "PostOpreation" pipeline and I wrote a  service.update(SelectedEntity). When I disable the update plugin then I will create product otherwise I am enable update plugin they give the error message("This workflow job was canceled because the workflow that started it included an infinite loop. Correct the workflow logic and try again.")

How to solve this? Please give me suggestion.

Thanks in advance!