If you dismount by clicking your mouse, on paladin at least, the weapon illusion is not displayed. However, if you then mount up again and dismount with the same key, the illusion does show up again.
At the time I made this post, I was using the vorpal illusion. Now I have also tested bronzewood, feytouched and holy avenger, these ones work fine after dismounting by attacking. So only some might not work properly, like the vorpal.
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On Paladin if you are using either Wings mount and interact with something that dismounts you, your shield doesn't reappear.
At the time I made this post, I was using the vorpal illusion. Now I have also tested bronzewood, feytouched and holy avenger, these ones work fine after dismounting by attacking. So only some might not work properly, like the vorpal.