I know there were a few topics about this bug, but apparently
@ZOS still don't have a solution for the problem. I made a video guide of how to lose this buff just by entering/exiting a Cyrodiil cave. As you can see, I don't do anything except going to sneak sometimes. Also I can confirm it's not related to race/class/vampirism/gear, because I had this bug on my another non vamp nightblade and templar both in previous patch and now.
I hope ZOS will investigate this bug more throughly, because it's probably the most annoying thing at the moment. Sometimes I notice I don't have Battle Spirit too late, when I got 1 shot, and sometimes I hit other people for 20k+ because they don't have this buff.
Anyone who knows other methods to reproduce the bug, feel free to post here

https://youtu.be/YyBVuIS7xSM
Time marks: 1:18, 2:20, 3:50, 4:45, 6:05
World's First Cloudrest Hardmode + Speed Run + No Death w/ HODOR
Tick-Tock Tormentor & All vHoF Achievements done w/ Chimaira
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