Uruks being harmed by sunlight, as I recall it, is thematic throughout season 1 of "The Rings of Power". Namely:
- Adar mentions himself being the only uruk who can withstand sunlight;
- The whole business of tunneling down the Southlands;
- Their plot to trigger volcanic activity so that the sky above Mordor may be darkened perpetually.
However, in season 2 episodes 7 and 8, when they're cleaning up the stragglers the morning after the siege of Eregion, uruks seem to operate quite well in the sunlight.
Am I missing something? Has a reason been given in the series? Could there be an in-universe reason outside of the series?