I dont seem to be able to make the polylang plugin work with this theme. Only one language is shown in the language switcher.
In the polylang documentation, it states “Take care that your theme must come with the corresponding .mo files (Polylang automatically downloads them when they are available for themes and plugins in this repository). If your theme is not internationalized yet, please refer to the Theme Handbook or ask the theme author to internationalize it.”
Is Blog Inn internationalized ? If so, do you know why the plugin does not function ?
I am not sure about Polylang plugin as I have never used this plugin. It will be better if you post your query to their support forum. I am extremely sorry as I do not have enough knowledge of this plugin.