5 sourced reports, with what to check before you buy. Each one links to the page it was reported on.
Costly or dangerous
Mavic 3 7X telephoto camera loses focus and needed lens replacement
Owner of a Mavic 3 with DJI RC Pro reports the 7X telephoto loses focus and will not zoom or autofocus at 7X and above; it persisted across both controllers and firmware, and DJI replaced the 7X lens at the depot at a cost over $617.
What to check. The 7X telephoto is a known failure point on the Mavic 3. A camera/lens repair ran over $617, so check the telephoto focus before buying and consider whether the extra zoom lens is worth that replacement risk.
Mavic 3 controller loses connection mid-air at about 15 meters
Owner-reported on a Mavic 3 (dual-camera, non-Cine) that the controller drops the link about 15 m up, in multiple locations, on latest firmware and after re-pairing; the thread ends with the owner considering a repair shop.
What to check. A mid-flight link drop at low altitude is a safety-critical symptom. Before buying, verify the RC/aircraft link in the exact unit, and confirm whether the loss is the RC, the antenna, or the aircraft's transmission module.
Mavic 3 Intelligent Flight Battery fails to charge with the original charger
Owner Q&A on the Mavic 3 Intelligent Flight Battery: the battery would not charge via the Mavic 3 Classic with the original charger even overnight, no LEDs lit, and the drone would not power on; replies point to bad contact on the pins, defective electronics, or a defective cell.
What to check. A battery that will not charge or wake is a common failure. Check battery health and contact pins before buying, and know that a replacement Intelligent Flight Battery is a significant extra cost.
Mavic 3 power system ESC error requires a serialized ESC replacement
After a hard landing/crash on a Mavic 3, the owner got Power System hardware error 16100069 and ESC error 1608002F; forum replies say a persistent error means a bad ESC, and a replacement ESC must be serialized to the main board with special software that is expensive.
What to check. ESC failure leaves the drone un-flyable, and a replacement is not plug-and-play: it must be serialized to the main board, which costs extra and needs specialist software. Factor this in for a used unit that has had any hard landing.
Mavic 3 gimbal moves irregularly and triggers an app warning
DJI's own troubleshooting doc (German) lists the Mavic 3 among models where the gimbal can move irregularly with an app warning; one listed cause is gimbal hardware failure, and DJI directs the product back for inspection if calibration does not fix it.
What to check. Gimbal irregular movement is a recognized symptom on the Mavic 3; if calibration does not clear it, DJI treats it as hardware failure needing return. Lower severity because it is manufacturer troubleshooting rather than a widespread owner-reported failure.
These reports come from the pages linked under each item: owner forums, repair guides and workshops. They are not a diagnosis of any one unit, and a careful check of the one you are buying still applies.
Text from the Kriko Drones catalog, version 0.1.1, under the CC-BY-SA-4.0 license.