WordPress theme [Spectra One]Nav Menu Not Working in Mobile Devices: It is a question raised by a user. I provide solutions here.
What’s the problem?
A blank page is displayed instead of navigation menu while clicking the toggle icon in mobile devices.
The page I need help with: http://wp1.pro/
Mehraz Morshed

As illustrated in the snapshot: the official demo shows a white overlay menu once clicked on mobile (Step1 to Step 2) but it doesn’t work as expected in the user’s case.
Code to solve “Nav Menu Not Working in Mobile Devices”
Just add this CSS into your additional CSS and it will work:
.wp-block-navigation__responsive-container-content ul li a{color:#000;}
How to add additional CSS?
First, go to click on the “Customize” button in WordPress.

Then click on “add additional CSS”

There you can add the code.
Copy the above code and paste it into the “Additional CSS” field and Don’t forget to Publish!

Please note that modifying the code requires caution. Always make a backup of your theme and site before making changes. The best way to check them is by testing them on the staging site(s) and if you have a third-party plugin, consider plugin conflicts as well.
Hi Victor.
Unfortunately, this isn’t working for me, and the overlay menu is still showing a blank page. The menu has always worked on my homepage, but doesn’t work for any subpages. Could you assist?
Hi Tessa,

Sure I’d like to help. But when I visited subpages, menu seems to work alright.
Could you please give me further info? You might as well contact me at admin@wputopia.com