Forts and keeps normally does not re-focus you if you are damaging heroes with damage over time effects (Dots).
Like Lunara for example will not get retargeted by fort after moving out and in even if she has dots on 5 people.
BUT the Tychus level 7 talent that adds a dot to your grenade makes the fort target you.
Already died 2 times this way please fix this annoying bug.
Murky’s Wrath of Cod is also similarly not marked as a Damage Over Time effect.
Speaking of the grenade talent, did they ever say anything about the damage over time effect prevent mounting up? There are many more powerful dots that do not prevent you from doing so. I believe it also had some other issues where the additional follow-up damage would interrupt channelling of the objectives as well.
It took a while, but Blizzard finally acknowledged it as a bug today. It is getting fixed next patch.
Happy holidays all, btw (if anyone is reading these topics during holidays…)
Wonderful, if only they had one centralised hub filled with frequent reports for someone to have it noticed it earlier 
(both of these bugs are much older than 9 days)
Glad that will get fixed, hoping before 2022 though.
Also just realized today this DoT even stops Zul’jin’s regeneratin’ ability.
They said a balance patch of 24 heroes is coming “within the next week”, so I hope Tychus is among them.