What does "act up" mean?

For a device to malfunction When technology behaves erratically or causes problems intermittently.

How do you use "act up" in a sentence?

My phone is acting up again. The printer has been acting up all week. When the wifi acts up, restart the router.

Phrasal Verb BritishAmericanAustralian ★★★★☆ Common informal

Meaning: For a device to malfunction

设备出故障

Que un dispositivo funcione mal

デバイスが誤動作する

기기가 오작동하다

When technology behaves erratically or causes problems intermittently.

技术设备运行不稳定或间歇性出问题。

Cuando la tecnología se comporta de forma errática o causa problemas de forma intermitente.

テクノロジーが不規則に動作したり、断続的に問題を起こすこと。

전자기기가 간헐적으로 이상하게 작동하거나 문제를 일으키는 것.

Base verb: act

Particle: up

Separable: No — the verb and particle stay together

My phone is acting up again.
我的手机又出问题了
Mi móvil está dando problemas otra vez
またスマホの調子がおかしい
또 휴대폰이 말을 안 듣는다.
The printer has been acting up all week.
打印机这周一直有问题
La impresora ha estado dando problemas toda la semana
今週ずっとプリンターの調子が悪い
이번 주 내내 프린터가 말썽이다.
When the wifi acts up, restart the router.
wifi出问题时，重启路由器
Cuando el wifi da problemas, reinicia el router
Wi-Fiの調子がおかしい時は、ルーターを再起動してください
와이파이가 말썽일 때는 라우터를 재시작하세요.

Context: devices, problems, malfunction

Tone: frustrated

From children acting up meaning misbehaving.

Era: Modern

Generation: All ages

Social background: Universal