After M2 upgrade success.phtml
template file not called at order success page.
while onepage.phtml
file is called at onepage checkout page.
Both file location is same but still success.phtml
file not called:
app/design/frontend/Packg/themename/Magento_Checkout/templates
success.phtml
onepage.phtml
Note: I have also try to add/remove checkout_onepage_success.xml
file in layout folder.
checkout_onepage_success.xml
you added and what is the content ? – Vinz Aug 31 '18 at 15:17