Apache server not using the correct version of php

Question

I want to switch my apache2 server from php5.6 to php7.4, following this stackoverflow solutions. However when I switched from php5.6 to php7.4, I get php5.6 then when I switched from php7.4 to php5.6, I get php7.2 instead. It wasn't like this before, please advice thank you.

php5.6 to php7.4 ( server used php5.6 )

php7.4 to php5.6 ( server used php7.2 )

Answer 1

I don't know the cause but a full uninstall and reinstall of php on my ubuntu fixed this.