Customizing another creator's scenario

I'm new to FictionLab, and I was wondering about something.

I tried to 'customize' scenarios from other creators, both to tweak certain things, and sometimes just to make a copy of the scenario for myself (preventing any risk of the scenario being deleted).

One thing I've noticed, however, is that unlike scenarios I create myself, where I can select to make the scenario 18+ if I want, that option is not available for customized scenarios. I thought it was just to follow the original desire of the creator, so I'm fine with that.

But I also noticed that when I customize a scenario that is originally an 18+ scenario, my modified customized version no longer has the 18+ tag. Is there a way to avoid this change, and keep it as intended as 18+?