In Version 14.9.0, I am unable to add a fluid other than water to the infinite fluid supplier on a server world. On a single player world, I can add fluid. I am trying the diesel fluid from Silent's Mechanisms. I also tried lava with the same result. Works fine in single player, but not on a server. Tried in creative mode as well.

First of all, I define 2 modes. CHEAT MODE will supply any kind of fluid. NORMAL MODE supplies only water.
In v14.9.0, the block placed by item got from creative tab works in CHEAT MODE whatever player's mode is. The supplier got by other ways (crafting, give command, etc) works in NORMAL MODE even if the player is creative.

I uploaded v14.9.1, which has texture change. CHEAT MODE supplier looks slightly pink. (NORMAL MODE had no changes and looks white) As same as v14.9.0, supplier mode doesn't have anything with which gamemode players are in.