Thank you for contacting Telerik Support.
One possibility is that this element which is located by your find logic is located somewhere off the screen when Test Studio attempts to make a real mouse click (DOM-click method would still work). To rule out this possibility, please try to add a MouseHover() action followed by a long delay (eg. System.Threading.Thread.Sleep(5000)) where you would normally make this MouseClick. If you find that the mouse hovers over a corner of the browser (instead of the intended button), then the found element is off the page and you may need to refine your find logic.
If my suggestion above doesn't help, please provide us with the means to reproduce the issue. A copy of your test along with access to the application would allow us to do so. If direct access is not possible (eg. app is local and/or private), we can instead attempt to "simulate" your app through a captured Fiddler trace which you can also attach to this ticket in a zip. If you are unfamiliar with how to create one, this link
will provide you with step-by-step instructions for download and use. Alongside the previous instructions, please make sure to enable the 'Store binaries' and 'Decrypt HTTPS traffic' options prior to starting the capture (see image). Thank you for helping us advise you.