I see this has been covered a little before here:
However, is there a way to get this to work on same-page links? I.e. can it collapse on click so that the page scrolls to the anchor and the menu collapse back to original state?
I hope you are well today and thank you for your question.
You can achieve it using small custom plugin solution shared in the following topic.
It is working fine on my test site.
This can be due to plugin conflict on your site so please try temporary deactivating all plugins except Unyson and provided Custom plugins and see whether everything works fine and then enable the plugins one by one to see which plugin is conflicting if any.
The issue is fixed in the below latest version of theme so please update your theme.
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You can update it by either deleting existing theme and then install latest theme version of it or use the following plugin to update the theme.
After activating the above plugin just install the downloaded theme on your site.
You won’t lose your site content after updating the theme but for safer side you can take backup of your site before updating the theme.