I cannot seem to change the subtitle in the customizer, and also not with the plugin Polylang. 

I checked several other tickets on the issue, for example, changing the homepage template etc. 

I have the Salient template installed. 

Thanks in advance.
Felix

Thanks for the fast reply. 

Despite using the polylang plugin, you might have some idea, suggestion, or location to look for the solution?
Thank you, 
Felix

Thanks Tahir,

I disactivated the polylang plugin. 

I try to change the subtitle in the customizer. 

In the screenshot, you can see that my actual subtitle is different from the one that I filled in the customizer. 

Thank you, 

Felix

When I have Polylang activated, I have changed the subtitle where it says 'ondertitel,' in the image, which means subtitle in Dutch. 

There, you can see that I have the three different translations from the Dutch subtitle that I had in the customizer. But, that subtitle does not show when visiting the website.

If you have no idea, I will contact Polylang,

Thanks a lot Tahir, 
Felix

That did not do the trick. 

For some reason a simple thing as changing the subtitle seems impossible, haha. 

I will keep on searching for it.
Thanks

For anyone who has the same problem with changing the subtitle of the WordPress website that has the salient theme installed and who has several other plugins like Polylang, I did the following:

What you should do is change the home page to a salient template. You do that by going to -> pages -> all pages -> your home page -> quick edit -> on the right, you need to change the template to a salient one. What you should also do, and what Tahir mentioned, is deactivating all kinds of plugins that could have an effect when updating the WordPress website. 'Try deactivating any minfication and caching plugins'.

These things did not work for me, so what I did was installing the Yoast SEO plugin. After installing that plugin, you can change the SEO title of any page. Which means you can manually change the subtitle of your home page. Go to that homepage, edit it, and scrolling down. There, you should be able to change the SEO title, by clicking on 'edit snippit.' 

Not sure if still relevant, but I recently published stable version just for this situation - Add Polylang support for Customizer.

Maybe other lost souls can find a use in this. Sorry for spam.