I just activated the redirection of my website to my domain and saw that all icons are not display correctly on my domain website like on my webspace website. I just see an empty rectangle.
I hope you are well today and thank you for your question.
This is happening on your site because your new site still contains references to your old site causing the issue as shown in the attached screenshot.
Please make sure you have updated old site URL to new one in your site General Settings as displayed in the second attached screenshot.