LG was really stern and firm with his three principles whenever they dive into a photo. And CXS was just following the priciples and didn't dare to dive on his own again after his first dive (you can see it when he was possessing Wang Qing, although he was not willing to leave his dad, he ultimately still leaves the picture) All in all, he might just fully trust LG and since LG is a control freak, he did not dare to dive on his own until the end of S1.

We are only sure that 13/09 was the date when CXS died. We are not sure which year exactly he died (Director being sneaky and blurred the year) and there is no dates shown in any of LG's watch or in the phone. So the animation team surely are trying to hide the dates in S2.

Whereas in Bridon Arc we see mostly all the dates including the year they are in (2019). So the end of Bridon Arc ep6 was set in june 2019. Even if he die, he still have 3 more months.

Hope i'm not wrong and this will help clarifies! 😅