This is true.
Most sports grounds are oriented so that the main viewing area (the clubrooms)
are on the west side of the field. So that later in the day those viewing from
the club rooms are not squinting looking into the sun.
If the club house is on the west side, then usually the scoreboard is on the
east side (facing west, into the low setting sun).
This pic shows this common orientation with the scoreboard facing west. Not the best spot to watch the footy late in the day.
If your club has a scoreboard then hopefully the LEDs are bright enough to push through this low sunlight. If the LED screen is not designed well, then the image will be faint and VERY difficult to read the scores.
"Brighter is not always better", it's a balance.
If
the right balance is obtained on a scoreboard screen then you will always see
the scores in low afternoon sun. Even when the sun drops so low that it misses
the Mask and directly hits the LED.
The LED is actually still bright, BUT the usually crisp black mask appears
"Grey". Which reduces the contrast.
See this comparative test in low angled light.
Some more examples...