The bug
Repeaters, comparators and observers were recently changed not to update non-solid blocks in front of them. For consistency, this change should be extended to redstone dust and torches.

Redstone dust updates
Because this would be incompatible with redstone dust updating other dust around it, there would have to be 2 types of updates: normal block updates and "redstone dust" updates so the entirety of a redstone line could be powered.

Mods
Please let Mojang devs decide whether this is intended. Please also read the report carefully – it is different to ilmango's one.