The logic behind the KeyTips is a little more complex than that. When you release the Alt key (which is your case) the KeyTips of the RadRibbonView are shown as LeftAlt is the activation key for the KeyTips. The MS office KeyTips behave a little differently (they show up on KeyDown), we are aware of that difference and have a feature request to allow the RibbonViewKeyTips to be activated on KeyUp.
Also after your report we have further investigate the entire behavior of the MS Word KeyTips and we have found that while the Alt key is pressed and type any key from the NumPad keyboard the KeyTips are canceled and the special symbols are executed.
We will consider this improvements to the KeyTips as they will make the user experience more fluent and MS Office like. That is why I have logged that as a feature request for our RadRibbonView and you could track its progress in our feedback portal
I hope this information helps.
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