I'm not certain if this is a TR bug but I guess so, as no other mods (except some of my hand-made minor fixes for vanilla Morrowind) are installed on my Morrowind. When I see Almalexia (I mean the goddess, since I haven't TR_Preview.esm enabled) for the first time, there's a topic "task", which I guess didn't exist in vanilla game until dealing with fabricants on Plaza, so there was no checking for quest status (I guess it was assumed that no check was required since the topic opened only after attack). So, I keep the Mazed Band with me, the Plaza isn't destroyed, but I go on Almalexia's quests beginning with "A lesson in Power". I think some quest in TR opens the topic 'task' ignoring its crossing with the same topic in Tribunal.

P.S. Just looked in TES CS, there's even three quests that add a 'task' topic and, yes, there's only a "TR_ShowPower<10" check in Alma's dialogue.

P.P.S. I guess I won't be able to complete "A lesson in Power" because the statue isn't destroyed and there's no ladder down, but that's a mess anyway, should be fixed, I think.