This has been happening a lot lately, that i mess up doublecasts on Riven which isn't something that should happen after playing her for years but i noticed this couple of days ago. Before, when Riven would E, she would break the code and be allowed to doublecast like for example she could basically throw W+Q at the same time after E (basic). Shield was allowing this to happen for her, but after some time i noticed that shield doesn't pop out anymore in an instant as she dashes (E). She would Dash but after .3 seconds or something like that, she would Shield.
This frame of on and off shield was the time for a doublecast. Whenever i would try to doublecast in that frame when she dashes but shield doesn't pop out right away, i wouldn't be able to. In fact it would remember my input commands and do them as in order without me touching that key at that exact moment. But if i wait for that frame to pass and then do a doublecast i would be able to.
This was not the case with Riven before and this is causing so many mistakes and deaths. Often i would try to E+Flash into doublecast but when i hit that frame before a shield i would just E+Flash+W and just stand in place because that that point it wouldn't do the commands in order, it would just E W. But when i would do it without flash it would do it in order and remember the commands.
hard to explain unless you feel it for yourself.
If you watch the clip and slow it down you will be able to see how i am able to do a doublecast when hitting that frame with shield up and when i can't do it right after dashing without shield up.
I always thought that E in general is allowing Riven to doublecast but i guess it's the shield since i can't doublecast before shield shows up.