Do this first: common mechanical causes before you blame firmware

Navigation gone wrong / mower stuck or turning strangely

Check the cutting discs before anything else. A 3-month-old LUBA 3 suddenly lost the ability to navigate around a bush it had handled fine two weeks earlier, plus developed a bizarre repeated multi-point turn at each end of the yard: symptoms that read exactly like a firmware update that broke navigation. The actual cause: one cutting disc had come completely unscrewed and was sitting in the lawn, and a second disc was also partially loose. An unbalanced or partially-attached blade disc can throw off the mower's motion in ways that look identical to a software bug.

• Power off the mower and check that all cutting discs are fully screwed down and evenly seated.
• If a disc is missing or loose, don't just re-tighten and move on. Walk the area it was last mowing to find the missing screw or disc before it becomes a mower or mowing hazard.
• If the mower repeatedly reports being "stuck" near the same spot with no visible obstacle, check the front wheel shafts. Dirt and grass gummed up inside the front wheel sliding shafts causes this; cleaning them with WD-40 and a dry lubricant resolves it¹, confirmed independently by a second owner with the same fix.
• A chassis motor error (1028) can be caused by the same class of problem. Mammotion's own support response for this code is to check whether a wheel is physically stuck and overloading the motor before assuming a firmware fault².

Mower docks but won't charge, or charges intermittently

Several independent reports point to physical dock issues before firmware:

• Check the dock is level and rigid. Repeated dock-but-fail-to-charge behavior traced to the charging station mount going slightly "wobbly" after the ground underneath dried out and shifted during a heat period. Re-leveling and firming up the mount fixed it completely. Mammotion's own support team gives the same first troubleshooting step for docking/charging issues: confirm the charging station is on a level surface.
• Check the charging contacts for corrosion or dirt. Clean off any buildup.
• Test the charger brick's actual output with a multimeter if you have one, rather than assuming the charger itself is fine.
• While it's docked, lift the mower's front wheels 1–2 cm (⅜–¾ in). This shows whether the contact alignment itself is the issue.
• If you're on Android, Mammotion's support team has also asked owners to verify no battery-optimization setting is closing the app in the background and interrupting the charging handshake. It's worth checking in your phone's battery settings for the Mammotion app specifically.

General erratic behavior / "it used to work fine"

A simple clean-and-reset routine, reported independently as reliably fixing unexplained erratic behavior on LUBA 3 units:

1. Power off.
2. Clean the mower: brush or wipe mud, grass, and debris off the housing and wheels. Keep water off the underside and the rear panel where the charging key/connector goes; the blade and deck page says why.
3. Power back on.

Worth doing routinely whenever behavior seems off, before assuming anything is actually broken.

The app says the security key is not inserted, with the key in place. A LUBA 2 AWD owner wrote that mid-task the mower pauses and the app reports "security key not inserted". He could not move it or send it home from the app and had to walk out and push the key in again, after which it happened again⁴. A second LUBA 2 AWD owner has the same error, and says rebooting or just waiting it out also clears it⁵. A Mammotion staff account advised checking the safety key and its slot for dirt, foreign objects or damage, making sure the key is inserted correctly, and trying the spare safety key from the package. If it continues, it asked for the device name, firmware version and order number⁶. Another owner suggested spraying contact cleaner in the key's slot and cleaning the key's contacts, which is a tip and not Mammotion's advice. The second owner was told in troubleshooting that the mower may have to be sent in for service, and had not done so yet.

Grass or debris caught under the blade deck

If the mower is leaving uncut patches or the blade sounds like it's struggling, check for grass wrapped around the blade spindle before assuming a firmware "uncut strip" bug:

• Rotate the blade by hand (or with a screwdriver in one of the disc's holes) to work caught grass loose. There's no need to take the deck apart.
• This is more likely after mowing wet grass or heavy dew: several owners note it happens more often in the early morning or after rain, and that mowing more frequently (shorter grass per pass) reduces how often it happens.
• A "cutting disk is jammed" error (1202) isn't always grass. A piece of metal garden-fence wire tangled in the cutting disc, missed on a first visual check, has caused a persistent version of this error³.

Connectivity / RTK issues

If you're seeing "NetRTK disconnected," an inability to switch back into a specific RTK mode, or general remote-access flakiness:

• Test Wi-Fi and cellular (4G) one at a time: turn one off and test with only the other, then reverse. A conflict between the two is a common cause, and Mammotion support asks about it first.
• If a client site or install can't establish iNavi/RTK positioning at all (rather than losing it intermittently), the fix is sometimes structural, adding a dedicated RTK reference station, rather than anything on the mower itself.

Before you start a task near a street or property edge

Not a defect, but a preventable operational risk several owners learned the hard way: starting a task on the side of the yard that borders a street or sidewalk increases the odds of the mower getting physically stuck (e.g., high-centered on a curb) or, separately, becoming a theft target if left unattended mid-task. Several experienced owners avoid scheduling street-adjacent zones unless they're home to keep a watch on it.