Please disregard the previous bug solution, we finaly pin pointed the problem exactly.
The bug will appear if you turn in quest OUT of order of the guide.
eg The guide instruction is to turn in Quest1 followed by Quest2 but if you decide to turn in Quest2 before Quest1. Quest2 will be unticked when you turn in Quest1.
We are working on a fix for this and will release it asap.
You can resolve this issue temporarily by
1. Typing /reload to fix the guide.
2. Or follow the guide exactly and don’t turn in quest out of order of the guide to prevent it from re-appearing.
I’m sorry we didn’t discover this bug sooner, I will update you as soon as the fix for the addon is available.