Microphone gets disabled

I’m running Ubuntu 18 and Audacity 2.3.x - I have a good microphone connetcted through phantom power and it works fine. However, every time when I start Audacity the mic gets disabled and I need to keep open the system settings app to re-enable it.
Also, when Audacity is running, if I switch mic, or only open the drop down for available mic’s and don’t select anything, same happens.

Is this an error or simply something to live with?

How do you mean “disabled”?
Describe what I need to do to see this on my computer.

The microphone is still visible in system settings of the os but is inactive or disabled, until I click on ‘ok’ in the configuration tab for input.

There’s still very little information about what equipment you are using, how it is connected, how your computer and applications are configured or what you are clicking or the problem that you are describing, but my guess is that you are trying to access a single client ALSA driver with multiple client applications at the same time. What that means in practice is that you need to do either one or the other of:

  1. If you wish to use ALSA directly, ensure that you only have one audio application trying to use the device.
  2. If you wish to access the device by more than one application at a time, use PulsAudio

Thank you for this advice. I have successfully installd pulseaudio and pavucontrol and everything is now working fine.
Apologies for not describing the problem adequately - and thanks for the advice.