Synthesizer "Master Effect" set as default enables inconsistently.

I've struggled with this one for quite a while now, opening the Synthesizer tab and manually disabling the Zita1 effect whenever I opened Musescore.

I always wondered why it won't let me set "No Effect" as default, but it turns out the "Set as Default" button only enables after performing some kind of trick.

Wanted behaviour:
- switch to "No Effect", click "Set as Default"

What you have to do:
- modify one of the other effects, then switch to No Effect and hit Set as Default
or
- switch to No Effect, click Save to Score, then the Set as Default button magically enables

This is really inconsistent behaviour if you ask me.