Dictation is currently broken (Mac OS 15.4.1 (24E263), M4 MBA

I have to redirect Dictation's attention to the following path regularly:

I go to System settings > Sound > MacBook Air microphone

every few minutes. This is such a common problem that I have System Setting open in a separate window for this purpose, but it still takes time and it's distracting.

I am an author, and write a great deal every day. Much of my work is done via the mail interface, and I normally have to run through this same resetting or redirecting of dictation for every subsequent email I reply to. Sometimes it happens within the body of a single email.

The symptoms are simple: when I double press the Function button (Fn), which is the way I have dictation set up, the wrong tone will sound – this tells me that dictation has forgotten what it's using as an input, and no transcribing will happen. I then go through the same path as noted above, and half the time doing this and reminding dictation of what it source is will cause the correct tone to sound and dictation will work as expected. The other half it will not and some other strategy needs to be employed, including restarting.

I simply cannot understand why this is necessary and it is a truly tremendous waste of my time on a daily basis. If there were a better dictation app I would buy it, but I have tried them all and even with this problem, dictation is better than all of them in terms of accuracy.

And before anybody suggests, I have done all of the standardly recommended things including turning Siri On and turning Siri back off again I don't use Siri); turning off Dictation and turning it back on again and on. Restarting usually helps, like it always does with any problem, but this is distracting and time-consuming.