After upgrade to Plasma 6, some icons are blurry

I have a high DPI display. On X11, I scaled the display to 125% by forcing the font DPI to 120 (which is 96*1.25) as a workaround since Plasma's display scaling always caused slight blurriness of icons. Since the upgrade to Plasma 6, this trick no longer worked and I got back the same problem of blurry icons, especially annoying in the taskbar.