I noticed, especially in vMA and vet dungeons that sometimes I'd experience noticeable input lag (delay between pressing the button and the ability triggering). The delay can be anywhere from only just perceptible (ms) to as much as 3 seconds. When you are spamming a key to get your shields to refresh on your sorc with a full magicka bar in vMA, you are just plain dead. I know this is client side because after I respawn at the wayshrine in vMA I'll often have 3 or 4 buffs trigger in quick succession that have been queued up because of the delay.
I noticed this suggestion in the forums of a couple of other games I play that require next to zero input delay and thought I'd try it. I did notice a difference, but the jury is still out for me. I have no need of this feature so I'll leave it off (didn't even know it was there tbh).
TL;DR disable "xbox game dvr" as follows:- Search "Xbox" in windows taskbar's search bar
- Click on the Xbox application icon to open it
- Find the settings icon (a small gear) on the taskbar to the left side of the Xbox application's window and click on it to open the settings menu
- Find the Tab labeled " Game DVR" and select it
- Slide the switch to off to turn off the Game DVR feature.