HUB75 + led strip on teensy 4.1

Hello
I’m using a teensy v4.1.
I’m trying to use a HUB75 panel + smartled shield to display text and GIF → OK
Also trying to load LED animations on a separated strip (144 LEDS) → OK
But when the 2 programs come together, my LED strip is not working properly :

  • I see frames drops on the HUB75 display using Adafruit Neopixel or FastLed for the LED strip
  • or the LED Strip is extremely slow when using WS2812Serial, despite it is famous for being compatible with other devices using interruptions such as my Smartled Shield.

Do you have any idea what can be wrong ?
Thanks a lot
Sebastien