It never left.

I have noticed a slow return.

It was pretty good for a while. No hits or aiding those who are fighting with buffs or heals for 10-15 seconds and you dropped combat. That was about a year ago up until a month or so ago.

Now it is back to the old way. Not 20 minutes like the OP for me. But certainly 60-90 seconds being completely removed from any fighting and finally dropping combat.

It takes so long.

I really hate this bug For some reason, when I'm on my templars and wardens, I suffer from it the most as it occurs much more often and for longer periods of time. Just few days ago I was about to port through transitus shrine... Out of nowhere "Entered combat"

I got hit with it multiple times in the last 24 hours, the most irritating one was locked in combat mode for 20 minutes - I walked (couldn't mount my horse) to where I was pretty sure there would be a fight and walked up to an enemy player, hoping that at least death might fix it - but he stood for a few seconds in front of me looking at me like I was insane then walked away and attacked someone else. Probably thought I was laying some sort of trap

I did eventually end up coming out of combat mode - and I can cope with a slight delay - but being stuck in combat for 20 minutes after your last fight is quite plainly ridiculous.

EDIT: During a lot of the time I was flagged as in combat, I moved well away from any areas where combat was happening, and went into sneak mode where I remained undetected for 10 minutes during this time - so it's not like I was being followed by someone I hit earlier.

Its in Pve as well.