In Sitefinity 15.4, a Kendo Grid with a filterable dropdown can display a ? character before each name while typing in the filter. This has been confirmed on pages that use the embedded Kendo bootstrap stylesheet shipped with Sitefinity.

The issue is caused by a rule in the embedded Kendo bootstrap stylesheet used by Sitefinity. The selector below applies a ::before pseudo-element inside the Kendo list and inserts unwanted content that is rendered as ? in the dropdown:

.k-list *::before

Use one of the following verified solutions.

Option 1: Add a CSS override

Add this style block after the Kendo resource references and before the Kendo Grid component in the template:

This is the most targeted fix and is appropriate when you want to keep using the embedded Sitefinity Kendo stylesheet.

Option 2: Replace the embedded Kendo stylesheet with the CDN version

Comment out or remove the embedded Kendo bootstrap stylesheet reference and use the CDN-hosted stylesheet instead:

<link rel="stylesheet" href='@("https://www.unpkg.com/@progress/kendo-theme-bootstrap@14.5.0/dist/bootstrap-main.css")&#39; />

If you use the CDN stylesheet in Sitefinity, add the following domain to the allowed styles sources in Administration:

• https://www.unpkg.com

In Sitefinity, add it under:

• Trusted Domains for Styles

Start with Option 1 if the goal is to resolve the issue with minimal change. Use Option 2 if you prefer to replace the embedded stylesheet entirely and are able to allow the CDN domain in the site configuration.

• This issue has been verified in Sitefinity 15.4.
• It may also affect other versions that use the same embedded Kendo bootstrap theme resources.
• The problem is not caused by the grid data itself or by the filter configuration. It is caused by CSS applied to the dropdown list items.