Your language disappeared, because your phone was originally manufacured for some other region/country where Hebrew is not spoken, and then someone (probably an importer/retailer that instead of buying devices intended for a Hebrew market bought devices intended for some other country, and then reflashed the device with Hebrew firmware without changing the product code of the device).
Now, when you did a firmware update, Nokia Software Updater updated to the firmware for the original region/country that the device was manufactured for originally.
Your language disappeared, because your phone was originally manufacured for some other region/country where Hebrew is not spoken, and then someone (probably an importer/retailer that instead of buying devices intended for a Hebrew market bought devices intended for some other country, and then reflashed the device with Hebrew firmware without changing the product code of the device).
Now, when you did a firmware update, Nokia Software Updater updated to the firmware for the original region/country that the device was manufactured for originally.