Dear @kaqurei,
Thank you for your topic.
Please let us know if you have a caching plugin installed, as your issue may be related to caching.
There are some plugins that generate a cache, including the Admin Dashboard.
So, please make sure the cache is not generated on the page where the given popup is enabled.
Clear all the caches and exclude the link, where the given popup is enabled from the Cache plugin settings.
If you are using a Cache plugin, then make sure that it does not store a strong cache and that the webpage where the given popup is enabled does not become static(HTML).
Check whether the Deactivate PHP cache is ticked from the settings of the cache plugin or not.
If yes, then please deactivate it.
The same is about the mobile version. There are some plugins that generate a cache for the mobile version separately.
You can disable the cache-generating process by deactivating the option from the cache plugin (if it has one).
After clearing the caches, try to check the case with either the Incognito mode or another browser/device.
If the feature doesn’t work for you in case you are a guest but works when you are logged in, most presumably, there is a cache problem.
The code works in the same way for both the logged-in users and guests. So, you need to clear the caches once more.
Please check this and let us know the outcome.
Thank you.