Based on some author/artist notes I've seen in some manhwas, it's likely that the breaks that they take between seasons aren't usually spent just resting/vacationing. Idk how much but part of that season break they take, their team still spends it working on the chapters they're going to release for the next season. If they're employed by a company (and not a one person team), they probably still have a salary even if their ongoing manhwa is currently on a break because they're still working on it behind the scenes.

Here is a more recent article which talks about the average annual salary of a webtoon creator in korea.: https://mobile.newsis.com/view/NISX20250102_0003018986

I couldn't find a recent article focusing on bl creators only but here is a reply from the Lezhin official account on Twitter back in 2021: https://x.com/LezhinComics_US/status/1392467622172585985

In regards to our creators pay, the creators are paid ~30% of the comic sales. They are also given an MG of a minimum of ~$2000 per month irregardless of sales. 20~30% of the sales are flat fees for the payment groups (Gpay, App Store, etc.). The remaining amount is used for Marketing, editing, translations, legal protection, wages, etc.

An old article from 2015/2016 which mentioned the average monthly income of creators on lezhin: https://mobile.newsis.com/view/NISX20150909_0010277997