do not rerender forms. You should add an a4j:outputPanel or a h:panelGroup to the the form and reRender this one instead:
console.log("i was rerendered!");
the script tag should give a hint, if the part of the page is actually rerendered.
Nope, it didn't help.
sorry, my fault. I've got mixed up with your forms ;-) I thought, the jsFunction would reRender its surrounding form but it reRenders the modal panels form instead!
and reRender the panel:
well, of course i didn't just copy-paste i put correct id into reRender parameter and it didn't work