We have one site where we are seeing an odd behavior in RadComboBox, that I've never seen in any of our other sites.
We have a lot of radcomboboxes throughout this site, some of which have pre-defined items, or items added on page load in the code behind. These comboboxes all work perfectly fine, exactly as expected.
A lot of the comboboxes however use load-on-demand to query items at runtime for the user's input. ALL of these comboboxes have the same problem. They seem to perform their AJAX postback fine, and get the correct data, and the items all get added to the combobox, showing the correct data.
The problem though is that the load-on-demand items cannot be selected. You can't click on them, you can't even use the arrow-keys to up/down to them and select one.
they don't show any errors in the Console tab on the initial page load, or the load-on-demand postback
they don't show any errors in the Network tab on the initial page load, or the load-on-demand postback
This project was originally written in ASP.NET 2.0, and we are upgrading it to 4.7.2.
Updated the latest Telerik DLLs, updated the latest jQuery libraries, updated the compilation nodes in the web.config.