Thanks for trying to help, i've get out from thereI don't have a test save for the flower cave fight, but that sounds like the correct progression. Talk to Aria? Check screen edges?
My main problem back there is when Serena arrive at the place where Aria is (my screenshot), Serena should be able to go there and get ambush by boss fight. But in my case, when i arrive at that place, the boss already defeated (they're lying on the ground) and i can't pass through there, therefore i can't talk to Aria.
I don't know how i get out from that problem, what i did just get out then get in again, repeatedly until finally i can pass it