what's wrong with my Flava??

[jop_pk]

My flava.. leaves of one rhizome r getting wither in the way i've never seen before. its whole tubes of this rhizome go wither. but other rhizomes r still fine. they'r producing normal leaf as i see. i put it direct sunlight all day with water level almost half of the pot. there were raining a couple of day before. not sure if it because of too much water or too strong sunlight? i live in Bangkok, Thailand now the temp is around 31-35 c (87-95 F)..hot!
or do you think it's getting into dormancy? i bought it while it had some phyllodia leaf. so i'm not sure it was during dormancy and i continue forcing them to grow. or its dormancy were finished and start to grow. at first i bought this plant it looked more healthy it produced sweet liquid around the tube but now it look a bit drier. however some rhizomes keeps producing new normal leaf and it look fine.
what should i do with my plant? should i set dormancy for it? is the hot temp here will be a problem? next month temp will be around 44 c (111f)
please help...
thank you so much!
Jop

first time i bought


whole plant now (one side)


wither leaf




rhizome


by the way.. hope you understand my poor eng.. lol trying to explain.. :D