Unable to set font & font size while styling Devanagari text in Writer

I am writing a text document where the content is in the Devanagari script (used by Indic languages such as Hindi, Marathi etc). When I try to customize and use styles from some template, however, I run into the following issue:

I have customized a style (say ‘Chapter’) to have 28pt font size and a font with support for Devanagari characters.

Whenever I use the ‘Styles and Formatting’ window to pick this ‘Chapter’ style and apply it to some selected text that is in the Devanagari script, it only applies the paragraph indentation, alignment and other settings for the selected style, but does not apply the font and font size settings. Note that the style is applied entirely correctly (along with font & font size) if the text is English/Latin, but not if the text is Devanagari. For Devanagari text, whenever I apply this style, the font and font size is set to ‘Mangal’ and 12pt respectively, and I have to manually change it to the desired font and font size.

The ‘language’ setting in the style is ‘English (UK)’.

I have the following version of LibreOffice installed in Debian Jessie:

Version: 4.3.3.2

Build ID: 430m0(Build:2)