Hi Brice,
Thank you for contacting Syncfusion support
We have fixed the Blazor webassembly delay loading issue and its fix has been included in the patch release rolled out on today. So, we suggest you to upgrade the Syncfusion NuGet version to latest version 18.1.43 to get rid of the reported issue.
Please let us know if you have any concerns.
Regards,
Saranya D