BlinkStick Strip does not fully turn off, 4 LEDs stay on

hi, I’m using homeassistant to control my BlinkStick Strip (8 leds USB ID 20a0:41e5 Clay Logic) bought on 29/09/2017. The Blinkstick Strip used to work well but over the last year or so it has become harder and harder to turn it off. After it has been on for an hour or so (especially when it is white), when I turn it off, the top (furthest from the USB plug) 4 leds stay on. If I then turn it on with a different colour, the top four leds might not change and only the bottom 4 LEDs change to the new colour. If I continue to swap colours, the fourth from the top LED will unstick and start turning on and off (or changing colours) with the 4 bottom leds. If I continue to change colours or turn it off and on, eventually all the leds will turn off.

Today, after being controlled by Homeassistant, the BlinkStick Strip had the top four leds white and the bottom four off. I then ran

$ .local/bin/blinkstick -i
Found device:
    Manufacturer:  Agile Innovative Ltd
    Description:   BlinkStick
    Serial:        BS015348-3.0
    Current Color: #000000
    Mode:          3
    LEDs:          unsupported
    Info Block 1:  
    Info Block 2:  

What could I have done to get my BlinkStick Strip in this state? Is it even possible to control the LEDs individually?

It is not HomeAssistant that is causing the problem I think. I ran:

$ .local/bin/blinkstick --set-color=white
$ .local/bin/blinkstick -i
Found device:
    Manufacturer:  Agile Innovative Ltd
    Description:   BlinkStick
    Serial:        BS015348-3.0
    Current Color: #ffffff
    Mode:          3
    LEDs:          unsupported
    Info Block 1:  
    Info Block 2:  

and then waited a while (many minutes). I then ran:

$ .local/bin/blinkstick --set-color=off
$ .local/bin/blinkstick -i
Found device:
    Manufacturer:  Agile Innovative Ltd
    Description:   BlinkStick
    Serial:        BS015348-3.0
    Current Color: #000000
    Mode:          3
    LEDs:          unsupported
    Info Block 1:  
    Info Block 2:  

The top four leds are white, the bottom four are black. I ran .local/bin/blinkstick --set-color=off again and all the LEDs went off. What’s going on?

I tested the Stick again, with some timing information this time.

:; .local/bin/blinkstick --set-color=white; date
Mon 13 Apr 16:47:08 CEST 2020
# all LEDs white
:; .local/bin/blinkstick --set-color=off; date
Mon 13 Apr 17:00:55 CEST 2020
:; # top 4 LEDs white, bottom 4 off
:; .local/bin/blinkstick --set-color=off; date
Mon 13 Apr 17:01:38 CEST 2020
:; # top 3 LEDs white, bottom 5 off
:; .local/bin/blinkstick --set-color=off; date
Mon 13 Apr 17:02:06 CEST 2020
:; # all LEDs off