I'm not sure how much of a known issue it is or if I'm reporting to the right place. But I'll tell you anyway.

When you complete the Fishkind Research quest, you will find yourself in the Fertility Temple. After you get out of there, you need to go to the "Temple of Thorns". In my case, I was enslaved for contextually irrelevant reasons before I ended up in the Temple of Thorns. With receiving the slave mark accordingly. With this mark it is not possible to enter the "Temple of Thorns" location and save Elise. You are not allowed into this location because Slaves are not allowed. However, this is not correct in this context, since according to the plot you enter there secretly. Thus, Elise cannot be saved, and the slave mark cannot be removed either.

Mechanically, Elise is alive, but not accessible. As far as I know, there is no other way to remove the slave mark. It's hard for me to imagine that this is a fair situation, so I had to resort to cheats.

If the situation is interesting: I was enslaved by Deepone in the Fertility Temple location and stayed there for some time. My Lona got out half-dead and got caught by a Fishmen patrol. I didn't know that it would be enough for me to simply show my documents and tried to escape. The result is predictable.

(Edited)Moderation takes a long time, so I’ll edit the message:

https://mega.nz/file/lz1WzC6I#byy8JBR3EoGJrjZ88NZf_ZdUvyqWEXMB1Qi0TqKjBA0

There is no save left on the main progress. I reproduced the complete situation, correct for the context. Used the "Cheats Mod" to provide yourself with food and potions. Saved time. I'm sure it couldn't "spoil" the situation.

Version: 0.8.9.2.1

(Sorry for the Russian language)

When trying to enter the temple, a dialogue occurs where Lona was discovered as a "Slave". You can leave or load into the “Road” Location, where Lona is attacked.

Having escaped from the guards, you return to the starting station.