Lights acting erratic - help needed please!

Issues
1

Hey guys

Im new around WLED and just completed my first project so hopefully you guys can help me.

I’m having an issue when I increase the brightness half of my strip starts to go crazy and erratic, video link attached below to show it.

If I go over 3000 mh on WLED half of the strip starts to go crazy

I am using BTF Lighting WS2812B 60 leds per meter with a total of 248 leds.

I am using an external power supply DC 5 V 20 A 100 W that i bought on amazon

I am using an Athom controller with built in wled

I can attach photos of my wiring to the power supply and controller if it would help

Would really appreciate any help please.

Thanks in advance!

2

You can’t power that many LEDs from the beginning alone. You need to add power injection wires. (Likely in the middle and far end. You may be able to get away with just the middle)
https://kno.wled.ge/advanced/wiring/#power-injection