Erratic dictation?

And now today, on a Tuesday, I am getting this dialog box in Word:

I get this dialog box with both my iPhone running EpocCam and a cheap, standalone microphone that I plug into the headphone jack on the back of the Mac Mini.

I post this report here in the Apple Forum rather than the similar Microsoft forum because I have the same inability to dictate into Pages. The only difference is that Pages does not yet give me a dialog bog.

Update. I plugged in an external microphone. It, too, does not work with Word or Pages.

Here is what the Sound Preference shows:

Word has not again given me the "Oops" dialog box that it gave me three days ago.

Does anyone have any guesses as to what is wrong with my Mac OS's sound input?

Changing the subject slightly, what is up with EtreCheck? When my last Mac was dying, I used EtreCheck often. I liked the application. It gave me years' notice of the impending failure of the computer, and I was ready when the time came. But I do not find EtreCheck in my current computer. (I would have expected it to come over in the restoration from the prior computer.) I do not find EtreCheck in the App Store. That absence gets my attention. The website for EtreCheck reports that the App Store no longer carries EtreCheck due to some unexplained policies. I am more than a little concerned about what are the policies of Apple that EtreCheck does not comply with. Why is EtreCheck not in the App Store?

A websearch turned up this webpage:  https://www.howtogeek.com/682514/microphone-not-working-on-a-mac-heres-how-to-fix-it/

I have an external USB microphone in the form of an iPhone SE (2d generation) running EpocCam.  One nice feature of EpocCam is that I can use a Wi-Fi connection between the Mac Mini and the iPhone, although for the moment I have them connected by USB.  I also have an external 3.5mm microphone.

I followed all the steps in this webpage.  

Both microphones appear in System Preferences > Sound > Input.  I have the input level for each set to maximum.

The preference Security & Privacy > Privacy was already set to allow access by most of the applications that have asked for access to the microphone.  Although, oddly enough, this permissions-preference pane does not show Pages as one such application.  I have used my iPhone/EpocCam with Pages recently.  I do not know why this preference pane would omit Pages.

One interesting item is that System Preferences > Keyboard > Dictation shows both microphones.   When I test each microphone in this preference, I see the sound level in the graphic moving up and down.

I then reset the NVRAM, or, at least, I think I did.  I shut down and then restarted while holding down the R, P, option, and command keys.   The Mac Mini started up normally, so I do not know if it reset the NVRAM in doing so.

My dictation ability has been highly erratic all week.   It has been a week since I last dictated through my iPhone.  In drafting this report here, I checked again.   I am drafting this report in Word.  Word does not accept my dictation.  But just now Pages does.   

Even though Pages is accepting my dictation as of this writing, it still is not listed as an application in the preference for Security & Privacy>Privacy.

Now, today, the dictation feature is working as it should. I am not aware of having changed anything in my hardware or software.

And now today the dictation feature is not working. Maybe it works on only Thursdays and Fridays.

Interesting. Neither the external microphone nor the iPhone records into Outlook, TextEdit, or QuickTime. So maybe the problem is with the Dictation tool.

I dunno. I feel awkward posting publicly the innards of my computer. May I send the EtreCheck report privately?

I hit "reply" to the last post in the thread. The reply is to idrisSeabright. I hope that you may find my "additional text" in the thread.

Thanks in advance for your assistance.