Website looks different on IE11 How can I solve that?

We have transfer this website www.safe-beleggen.nl to one.com from another owner but I bought the same theme; colorlib sparkling. Now the site is online again but at Internet Explorer 11 it’s not showing well. There’s a lot of white under the header that doesn’t belong there. Do you know what I can do about it? Example in the attachment.
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Hi @dianajacobs,

I hope you are well today and thank you for your question.

It seems you are using older version 2.3.2 of theme on your site so please try using latest version of it.

This can be due to plugin conflict on your site so please try temporary deactivating all plugins and see whether everything works fine and then enable the plugins one by one to see which plugin is conflicting if any.

Best Regards,
Movin