https://www.curseforge.com/wow/addons/tidy-plates-threat-plates/issues/514

Nameplate debuffs have the wrong timing. It always ends when 0.3 seconds remain. Timings shifted compare to original auras. Can I fix this?

Since Classic Path 1.15.0, WoW now supports aura durations natively; separate addons (like LibClassicDurations) are now longer necessary. This should also fix this issue unless WoW itself provides aura durations for these debuffs.