Sound devices don't always show up in pulseAudio plugin

It seems like about half the time I boot up my PC, the PulseAudio plugin will display all of my audio devices only half the time. The ones that go missing are two USB audio devices: THR5 (USB speakers), and XIBERIA (USB headphones). This has been happening ever since I installed Manjaro a few weeks ago. Whenever it happens I’ve been restarting the computer and that usually fixes the issue.

I’m wondering if there is something I can do to get the USB devices to work without restarting the machine… Perhaps restarting some systemd service or something like that?

I should add that I tried the obvious: unplugging and plugging in the USB devices. This doesn’t work.

You can restart Pulseaudio with this command

systemctl --user restart pulseaudio

Is this system dual-boting with a Windows OS ? if so you should turn off their ‘fast boot’ - Intermittent problem - sometimes no sound after boot

Are USB devices plugged in to a USB 2.0 socket on system ?
USB Audio devices may not like using a USB 3.0 socket or USB hub

Unfortunately, that did not work. PulseAudio restarted but the audio devices still do not show up.

I am not dual-booting with Windows.

The headphones are plugged into a powered USB hub. The speaker is plugged directly into a USB 3.0 on the motherboard.

I just recently rebooted and the audio isn’t working again. I plugged in a flash drive to the USB hub and the drive did not blink like it normally does, and the drive does not show up in lsblk output.

Perhaps this is a USB problem, not necessarily an audio problem…