Characters being deleted when changing backlight?

[nseidle]

(moved from OpenLCD issue reported by @mrmakeit)

Getting a weird bug whenever I try to change the backlight over I2C. Any time I do so, the screen will delete a character, usually the last one from the current message, though repeating the change will delete more and more characters. Any idea why this is happening?

import qwiic_serlcd
lcd = qwiic_serlcd.QwiicSerlcd()
lcd.begin()
lcd.setContrast(5)
lcd.clearScreen()
lcd.print("Hello World")
lcd.setBacklight(0,0,0)
#'d' should now disappear from 'World'
lcd.setBacklight(100,100,255)
#'l' should now disappear from 'World'

Tested on python3 with Qwiic_SerLCD_Py installed.

[CleoQc]

I am reproducing this bug.

Note that the bug does not happen with setFastBacklight()