I think some others have mentioned similar issues already. Yet, I don't think this issue has enough visibility, so I would like to mention some of the commonly known issues with stamcro (esp. in pvp in Cyrodiil) for more visibility and some others that I have been experiencing in order to hear from other players to confirm or share their experiences.
1- I think most of us are aware of the blastbones issues where it gets really bugged or even won't go off at all when there is a slightest lag or other activities going on around.
2- Totem. Again, when there are other actions going on around (doesn't have to be a large scale activity/fight), this ability also begins to stutter, sometimes takes way more attempts than other abilities to actually go off.
3- Spirit guardian. Not as bad as the other two, but still stutters sometimes.

I have been playing stamcro since release and loving it. I have also noticed that Necromancer abilities are overall way more susceptible to even the slightest server-side issues (lag, desynch etc.). I am not sure, but I am beginning to think that it has something to do with Necromancer class being the newest, hence, having the fanciest/different animations and that is somehow making these abilities more susceptible and bug out more often. Other abilities such as 1h/2h ones don't stutter at all(almost) I think this is because they generally don't have fancy animations. Similar thing goes with warden, where some class abilities sometimes stutters whereas the weapon abilities don't. But of course none of these are as bad as they are with Stamcro.

I really would like to hear what other old Stamcro players (esp pvp) are experiencing and if they can confirm these. And if this is as commonly seen as I believe, I hope to hear a word or two from ZoS if they are also aware and have any plans on working on it.