You may not be marking them because they are faulty, but because they are AI. The whole problem described by OP would be solved if there was some sort of distinction between AI translations and human translations. But I don’t know how they actually work, is there any confirmation that they are always the same in the same context? Are they really rated together with the user definition? I don’t think they should. But in general I don’t think I’ve been afflicted by the issues I’ve seen people reporting. I also don’t want to get much into how others use LingQ, but I think this excessive fine-tuning of translations may be detrimental.
I also think the icon for the AI should be changed, maybe some [AI] mark, had I not seen the forum announcement I might not immediately gather that it was an AI contextual translation.