Page scrolls when popup opens

Where should I click to trigger the popup with this scrolling behavior?

Thanks for letting me know.

You can see it happen here: https://nieuwbouw-opdewerf.nl/
Click on the top left banner.

I think your theme has a smooth scrolling function that captures the link to an anchor and tries to smooth-scroll towards it.

If you replace the URL for the banner to the JS equivalent for opening the box this won’t happen. The link you can use is:

javascript:Boxzilla.show(1190)

Hope that helps. If you have any questions, please let me know!

Great! That fixed it. Thanks!