So the mechanics of interruption seem to not be fully understood, so I will try and help explain it.

When ever you are in combat, a percentile chance is calculated.

Strength, the new resilience and how hard the incoming hit was all work to either decrease or increase that chance.

Once the calculations are done the "chance" of interrupt is set too the player.

Before the player can cast, dice is rolled to see if what they are trying to do has been interrupted.

The main things a lot of player don't seem to realise, is that the chance has a diminishing effect.

This means, that over time, the chance is reduced.  So it can still be present out of combat after a few seconds.

So, even if you just left combat or you just cloaked, if the guy who smacked you last hit you hard, high strength, or even a high level, you can still be interrupted on your next action.

There are 3 main ways to combat this.  Raise strength, raise resilience, or just wait a bit.