Blog only shows excerpt(summary) rather than full post when “Readmore” clicked

Hi,
for a while,my blog shows only excerpt (summary) and doesn’t show full page when “ReadMore” clicked though URL changes.
Site: https://www.test.factory9.com.au
have tried the following steps but didn’t work.
1. have tried updating permalink
2. have copied “cotnent.php” from parent theme to child theme.

Can someone please help, its been very frustrating issue for a while and no one could able to assist.
thanks
kris