I updated my iqoo Neo 9 pro to Trial funtouch os 15 update and it has some issue from which the major one is Battery drain issue like 

Battery is draining more faster. AS I charged my phone to 100% and by doing normal tasks for 1 hr make the battery to 86%.........

Hope iqoo connect you we'll fix this issue.....

Because as it is very important .

Please fix it...