Can I change the settings on my internal memory in my Huawei H868C phone?

[AC Question]

I have a Huawei H868 phone. According to the settings tab, I have 2.26 Gb of internal storage. I have used 316 Mb for apps, but it says I can only use another 212 Mb for apps? I do have a SD card in it, and understand the part about installing apps on the card, however why can't I use more of the internal space to install apps? On my old phones, I installed apps on the internal memory, and used the SD card for storage (music/books/etc). and this is what I would like to do with this phone - however I can't due to the limitations set on app installation.