Case reminder doesn't work

version: 7.11.3
xampp 3.2.3

Problem: Case reminder doesn’t work, after the time set. (the email reminder is send when new case creation only.)

workflow:
module: cases
Run: Always, All record
Condition: 1.cases - date modified - less than or equal to - date - now-15 minute
2.cases - status - equal to - one of - new,assigned to
action: send email, to - related field - Users: Assigned to

C:\xampp\php>php -i | findstr timezone
PHP Warning: Module ‘openssl’ already loaded in Unknown on line 0
Default timezone => Asia/Kuala_Lumpur
date.timezone => Asia/Kuala_Lumpur => Asia/Kuala_Lumpur

And i found my database not in correct timezone.
Example for a case:
04/15/2019 11:55am Date created (View Case) <- this is correct
2019-04-15 03:55:58 Date_entered (Database)

Okay it work,

But some time work, some time doesn’t work.
The email message $acase_date_modified value some time correct(GMT +8), some time wrong(UTC +0). :S :S :S
Why this happen. Can somebody help?