Paliaka 49-55 something break/bust/make worse?

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for the first time i made paliaka quest 49-55 around two weeks ago - any problems.

today i want second char make this quest and surprise - after killing hillas, papion disappears after few hits, little that - raises me injures, and i cannot see him! after few time, its over, and papion didn't more respawn, but his mobs after long time returns.

does not operate: /target papion, relog, re-enter to instance (after few ours)- papion disappear!

interestingly - from the second account the same problem, i have one char in second account.

what happens?

edit:
after morning server restarting everything return to its place - quest working fine!

p.