Hi,
first thing:
of course 3.2.1 translation will be incomplete for 3.2.2.
Why are you not able to use the 3.2.2 translation?
You could use the translation validator, it will show you easily what is wrong. But it won't tell you, if there are typos correction or string corrections missing:
https://github.com/phpbb/phpbb-translation-validator
Regards