Hello,
It is a strange issue, we have witnessed because at our Test Site we haven’t faced such an issue yet.
As we have checked, it seems that the Cache plugin was causing the conflict on your Site. When we deactivated the LiteSpeed Cache plugin then checked back the Site again regarding the concern. The respective pages were opening fine when clicked from the dropdown menu. So, it is a third party Plugin conflict not an issue at the Theme level.
Please check back your Site after completely clearing the browser and server cache.
Best Regards