Hello,
my XHP 50.2 glows a bit green for a short time after turning it off.
Like phosphorescence a bit.
From what comes this effect?
Could be from the emitter itself (SST-20 definitely have some afterglow regardless of driver) but if the light is running on a boost driver it’s likely because of that. The capacitor and/or other components in them hold some power which leads to a (sometimes fairly bright) glow which fades away gradually when the light is turned off.