MK5 wagon: early vehicles with brighter rear lights. Why?

Hi all,

a while ago I found out that the early models of the Mondeo mk5 wagon do have very bright LED taillights (not the break lights, but the regular rear lights when turning parking lights or low beams on).
Later model years (not facelift) seem to those lights strongly dimmed. I presume that the early and later models have the same part numbers for the lights.

On my 2018 Mondeo the rear lights definitely CAN do the higher brightness. I found that out when using FORScan to enable the inner rear LED lights as breaking lights also(those in the trunk lid). When stepping on the brake pedal (while parking lights are on), those LEDs increase their brightness by circa 30 percent, which is the standard brightness of the LEDs of the early Mondeo wagon versions.

In this video you can clearly see the difference in brightness between early and later model versions:
https://www.youtube.com/watch?v=yQ_iDONHwcs
See the right car, the backlight is much brighter.
 

Am I the only one who observed this strange deviation in brightness?

Do the very early models have different part numbers of the taillights?