Customization text reverses after update

Hi! Yesterday I did an update. I’ve lost all my text and email customization, they reverted to the original. How can I prevent this?

If I contribute to the Transifex translations how long until my updates are committed?

Just looking at the commits on GitHub…

Updates of translations into the code base are approximately every 7 days.

The last wait between translation updates was 10 days, the 6 updates previous to that were an average of 5.3 days part.

How did you customize the texts? Did you use Admin → Customize?
This problem was mentioned here a few times now (here, here and here), but the devs can’t reproduce it.

What version did you use before the upgrade? What version are you using now?

Yes, I did it through Admin -> Customize -> Text Content/Email Templates.

Currently using v1.5.0.beta9 +102. Before that I don’t know, forgot it. If there is some kind of a Update Log please guide me how to access it?

UPDATE: I’m using Bosnian language, not English, maybe that helps.

UPDATE 2: In other topic I’ve found a fix. I edited one of the customization text and all my other customizations/email templates are back.