I brought up the very same issue long time with 3.x version.

Let's say I create two topic prefixes:

[Active]

[Inactive]

Initially I mark some topic as [Active].

If then I want to mark it as [Inactive] I'd expect just to see [Inactive] prefix replacing [Active] prefix.

But no.

What I got is double prefix [Inactive][Active].

Makes no sense.

o-o