I’ve serched 3 days for a hardware bug on my selfdesigned PCB, did think about groundflooding and instable powersupply. PWM switching by logilevel FETs was my idea. Caps added, extra wiring for ground… nothing 
By loadcanges it will freeze and reboot.
At last, i tried a older FW on my ESP12 module - with 13.3 is my hardware stable 
Can somebody verify please, if FW 14.1 has a stability problem with RGBW PWM?
Thanks 
Update: different Hardware. A Wemos D1 with PWM RGBW GIPO 4, 5, 2, 15 run stable with FW 13.3, 14.0 b1, 14.0 b3 but mads trouble with FW 14.1, if you cange settings fast (freeze and reboot).
It’s not necessary, to drive logilevel FETs, you can test it “naked” software only 
Yes, many problems listed with v14.1 on github: Aircoookie - WLED - issues
Try 0.15-b1.