Welcome to the Forum! Best way to get that answer is to use the "Search" engine on this page. Enter "spots on TPO Roof" and then read for an answer.
The cleaning product I use for about everything is Simple Green. Roof, sides, carpet, inside fridge, anything. Works well diluted and for trouble spots I use it full strength.
Hope you find the answer. LB
Love the sunshine and warmer weather!
Lynne and Jerry RVM 105
2004 Winnebago Itasca Sunova / 2012 Toyota Prius / 2016 ACME EZE-Tow Dolly