MacBook Pro 2018 Random Restart > Previous shutdown cause: -20

I have MacBook Pro 2018 (Mojave 10.14.1) just brought it 3 weeks ago,

now i have random restart when i use it.

i only browse internet, play spotify but suddenly the screen goes black and it restarted.

it's very annoying, knowing im not use it for heavy task.

im checking with

log show --predicate 'eventMessage contains "Previous shutdown cause"' --last 24h

Result :

2018-12-02 21:23:31.803844+0700 0xb6 Default 0x0 0 0 kernel: (AppleSMC) Previous shutdown cause: -20

2018-12-03 04:49:02.918465+0700 0x266d3 Default 0x0 0 0 kernel: (AppleSMC) Previous shutdown cause: 5

2018-12-03 06:49:58.180398+0700 0x26d21 Default 0x0 0 0 kernel: (AppleSMC) Previous shutdown cause: 5

2018-12-03 07:30:06.076770+0700 0x2721c Default 0x0 0 0 kernel: (AppleSMC) Previous shutdown cause: 5

2018-12-03 09:50:55.501253+0700 0xb6 Default 0x0 0 0 kernel: (AppleSMC) Previous shutdown cause: -20

I searched on the internet about this -20 shutdown code, but i can't find the answer.

Had a chat with apple.support, i did SMC Reset but the problem still persist.

Is it a new kind of shutdown code from Mojave? Since

I can't find any answer on the internet, please help :(

Any opinion and solution will be appreciated, thanks!