Firstly, check the “Find usage” for your microflow to make sure there are no unknown places 😉.
More details are possible with using breakpoints, useful to do a walk through your microflow and called sub flows eventually.
This can happen for the microflow that are “source” microflow. (Datagrid with source microflow for example).
This kind of microflow is launched every time you refresh the element of the page. So maybe you refresh your object twice here.