Custom translations won't work for all strings

Hello we use 10.3.0 version of tutor.
We have an issue with the translation of some of the strings, some are translated and some others no.
There are some similar questions but since there was from older tutor versions i’ve made a new topic.

We are editing the the po files from the edx-platform repo we used this tutorial

our files have the translations, but on the site the strings are not translated.
And for example even the register button has a greek translation which is not ours but the one that the open edx last release has, something strange…
Is this something that has to do with the compilation of the image?

@regis I don’t know if I described the issue correctly, if you can please check.

Thank you in advance