As I cannot include a link with the game replay on HS replay I can only describe it. When I imprisoned Questing he was 9-4, when he woke up he had 9-7 statline.
The replay reveals that when the Adventurer goes Dormant, its stats change from 9/4 to 2/0. When it awakens it goes from 2/0 to 9/7. I suspect this is a consequence of two rules: 1) A Dormant minion is not affected by stat buffs. They're still attached but evidently not active until it wakes back up. 2) A Dormant minion cannot have less than 0 health. Not sure why such a rule would need to exist since they clearly cannot die anyway, but it fits the sudden reduction in damage.
https://us.forums.blizzard.com/en/hearthstone/t/questing-adventurer-healed-by-3-health-after-being-imprisoned-by-maiev-shadowsong/32069
The replay reveals that when the Adventurer goes Dormant, its stats change from 9/4 to 2/0. When it awakens it goes from 2/0 to 9/7. I suspect this is a consequence of two rules: 1) A Dormant minion is not affected by stat buffs. They're still attached but evidently not active until it wakes back up. 2) A Dormant minion cannot have less than 0 health. Not sure why such a rule would need to exist since they clearly cannot die anyway, but it fits the sudden reduction in damage.
Also shown here: https://www.bilibili.com/video/BV1QQ4y1N7up - at 5:28