Today while doing the analysis of existing system in New Form Rendering, we realized that the SetValue function used on onChange of an attribute was in turn triggering the onChange event for that field.
We basically had an option set field whose value we were setting based on certain condition on onChange event of the same field. This was working fine in Legacy Form Rendering and also in vanilla instance of Dynamics 365.
Only in new form rendering we were getting this issue of infinite loop.
I see the similar issue discussed in the forum
We are planning to raise a product support ticket for the same. Let us see what solution the product team will come up with.
Hope it helps..