Well this issue just got weirder as I was trying to pin down exactly what was going on. Anyway. The issue is with placing a log (for example) with a diode on one side outputting into the log, and a comparator on the other side reading from the log. Changing the diode's Powered status updates the log, but not the comparator on the other side. However, a comparator placed on either of the other two sides of the log will be updated properly (in fact, a comparator placed on the East side of the log caused the South comparator to update, but a comparator on the West side did not). Redstone dust used in place of a diode will update the comparator, even if that redstone dust is powered by a diode.

can confirm:

forge version 36.1.0
morered: 2.1.0.1

Using normal repeater:

Using a moreRED diode:

Then forcing a block update on the comparator:

The issue does persist with (it seems) all redstone related updates: