Platform:
Windows 7 64bit

ISP:
VM

Type of Internet Connection:
Fibre Optic

Internet Connection Speed:
150Mbps

Date & Time:
11:35PM GMT / 17/03/2019 (but anytime)

Frequency:
Always

Character Name:
Sirmarki

Race:
Hume M

World:
Asura

Main Job:
WAR (99)

Support Job:
SAM

Area and Coordinates:
Moh Gates

Party or Solo:
Solo with trusts

NPC Name:
Apururu, Koru-Moru, Ygnas

Monster Name:
Any

Steps:
If a WHM trust (in this case Apururu or Ygnas) cast Haste on me first, Koru-Moru will not cast Haste II to overwrite it, meaning I only get the lower tier haste. Haste has to be cancelled off, in order to get Koru-Moru to cast Haste II on me.

It's as if Haste carries the same ID/slot as Haste II, so as far as the trust is concerned, if Haste(I) is on the player, there is no need to cast Haste II on them.

This may not just be exclusive to these particular mages, but these are the ones I generally play with.