I have this same issue as described here: https://colorlibsupport.com/t/mobile-menu-issue-with-anchor-links/
For example, when clicking a read more link at the blog, the anchor prevents the mobile menu from working.
You can test it here: Superlaiffin odotettu sovellus pian ladattavissa! - Superlaiffi
Hello there,
I hope you are doing well today.
in some cases, if you have the anchor link as " #about" in stead of the full url it can cause issues. Please try replacing it with the full url such as https://website.com/#about.
Best Regards,
Support
Hi,
This really really really doesn’t fix the problem.
Also, please note, this happens with read more links, that are built in to the theme.
As I mentioned in my original message, you can test it here: Superlaiffin odotettu sovellus pian ladattavissa! - Superlaiffi
Hey there
Please test an original theme without modification and on deactivated plugins, let me know if you still have same problems, i can help if you have our theme unchanged but if you modified it (i see) then the author of the modification must help
I tested this and it still doesn’t work.
Here, I made you a whole new WP installation, without any plugins or a child theme: Sivua ei löydy - Superlaiffi
It has the same issue, as you can see. The mobile menu doesn’t work with the read more anchors.
This isn’t something I broke. It’s a bug in the theme.
hi there
Send me your admin details for this test site, i will check it
You can test this on your own demo, here: https://colorlib.com/shapely/template-more-tag/#more-996
The same issue happens on your own demo when the mobile menu is used. 
Hey there
Sorry for this inconvenience, i just reported this problem as a bug, here is the link where you can see the progress:
Thanks!
You are welcome and sorry for inconvenience 
Any news on this? The issue has been closed on github, but the latest update didn’t fix it.
HI
Can you try to update theme from github repo and no from wordpress directly? most probably this fix is not yet released in wordpress repo
I see. Well, must wait for the WP repo release in that case.
You are welcome