Unicorn Hat problems

Hi, after using Unicorn hat with a PI3 for more than 2 years, frequently all leds on the board light on randomly; sometimes a reboot resolve, but not always; I reinstalled sw, changed the board and the charger but the problem is the same. Do you have some suggest?

Do you have anything else connected to that Pi?
Install any new software recently?
The Unicorn Hat uses GPIO 18 to control the LED’s. That Pin can also be also used for PCM (Pulse-code Modulation)

No, the situation is always the same. The strange thing is that sometimes after a reboot averything works well but after some minutes, again all the leds light on randomily and with random colors.

Ok, I’m not sure whats going on to be honest. I have the Unicorn HD, it uses SPI and thus works differently.
About all I can suggest is to make sure its firmly attached to the Pi’s GPIO header and that nothing on the Pi is touching the underside of the Hat.