DJI Mic keeps disconnecting: how to fix dropouts

A DJI Mic that keeps disconnecting is usually fighting its radio link: the transmitter is too far away, a body or wall is between it and the receiver, or a crowded 2.4 GHz band is causing dropouts. Keep a clear line of sight, shorten the distance, and move away from Wi-Fi routers. If it shuts off rather than drops out, an auto-off setting or low battery is the cause.

Rated range in open air (FCC) — DJI's rated maximum range, measured outdoors with no obstructions or interference. Walls, bodies and busy 2.4 GHz Wi-Fi cut real range far below this.

Dropouts vs. shutting off

First figure out which you have:

Audio crackles or cuts, then comes back: a signal problem. Read on.
The transmitter turns off: check battery (solid red light means 0 to 10%) and Transmitter Auto Off on the Mic 2, which powers it down after 15 minutes when it isn't connected or recording.
The receiver turns off: Receiver Auto Off (30 minutes without a linked transmitter) or Power On/Off Camera Simultaneously, which shuts it down with the camera.

Fix signal dropouts

Keep line of sight. The Mic 2 and Mic Mini use the 2.4 GHz band. DJI's range figures (250 m for Mic 2, 400 m for Mic Mini under FCC rules) are for open, unobstructed outdoor space. Indoors, expect much less.
Mind the body. People absorb 2.4 GHz signals. A transmitter on someone's back, or clipped under a jacket while they face away, can drop out at short range. Clip it on the front and keep the receiver facing the speaker.
Mount the receiver high and clear. On a camera's cold shoe, not inside a bag or behind a monitor.
Move away from interference. Wi-Fi routers, crowded event networks and other 2.4 GHz wireless systems can disrupt the link. Turning off nearby devices you don't need helps.
Charge fully. Low batteries make everything less reliable.
Update firmware. DJI's release notes for both mics include stability fixes. Update the Mic 2 by computer and the Mic Mini in the DJI Mimo app.

Protect your recording. On the Mic 2, turn on internal recording, so each transmitter keeps its own backup on its 8 GB storage. A dropout then costs you nothing. See DJI Mic 2 internal recording. The Mic Mini doesn't record internally.

Keeps disconnecting from a Mac

When the Mic 2 receiver is used as a computer microphone over USB-C:

Use a standard USB-C charging cable or DJI's USB-C phone adapter, as DJI's manual recommends, and plug straight into the computer rather than a hub.
Select the receiver as the input in System Settings > Sound > Input, and again inside your recording or meeting app.
DJI says not to use the receiver for data storage. Plugging it in for files and audio at the same time can cause trouble.
Turn off Receiver Auto Off if it drops after a long silence.

More detail is in DJI Mic with PC or Mac.

Bluetooth connections drop

DJI's range figures are for the transmitter-to-receiver link. When a transmitter is connected straight to a phone or Osmo camera over Bluetooth, keep the device close, avoid putting your body between them, and turn off other Bluetooth audio gear. If drops continue, use the receiver instead.

When it's the hardware

If one transmitter drops out at a few meters while the other is fine in the same spot, swap their positions. If the problem follows that transmitter, contact DJI or start a repair. For range expectations, see DJI Mic 2 range. The DJI Mic Mini has the longer rated range of the two.