I have one potential fix that helped at least me. I enabled Battery Saver on developer options and i have been able to get thru the day with ease. I have charge limit set to 80% and have charge left after the day.
Battery saver works lot better, at least for me, than Ultra durable mode that asus has.
Asus needs to do something for this battery problem because i sometimes had to charge my phone middle of the day and it just feels crazy when you have 5000mah battery on this phone.
I know this is just a temporary fix but i hope it helps you guys as it helped me.