Inconsistent

[Dave Paprocki]

Not consistent; showing inconsistency;
irreconcilable; discordant; at variance, esp. as regards character,
sentiment, or action; incompatible; incongruous; contradictory.

[Magaret]

Lacking [consistence] or [continuity]. The opposite of [consistency]. When something is inconsistent, it changes as opposed to being [unchanged].

[Kit]

If a reason, idea, opinion, etc. is inconsistent, different parts of it do not agree, or it does not agree with something else:

[Kit]

Not staying the same throughout.