The PEI plate is the first thing to keep clean. It is a flexible, removable spring steel sheet, and oils from fingerprints or dust picked up in a workshop are usually why a print that should stick just does not. Wipe it down with isopropyl alcohol before a print session, or any time adhesion looks weaker than the last one, and let it dry fully before loading filament. Because the plate lifts out in one piece, this takes a minute at most, and it beats re-leveling out of frustration after a print lifts halfway through.
Check the filament runout sensor and the tube leading to it every so often. Dust and small bits of filament can build up around the sensor over months of use, which can cause false runout alerts or let a sensor miss an actual empty spool. A quick glance when loading a new roll usually catches this before it becomes a problem mid-print.
Look over the quick-release nozzle assembly from time to time, especially after printing anything abrasive like PLA-CF or PETG-CF. Residue tends to collect around the nozzle tip and the release collar, and it is easier to clear while soft than after it hardens into a ring. Since the nozzle detaches without tools, this is a habit worth building rather than a task to keep postponing.
Update the firmware whenever Flashforge publishes a new release. The printer’s firmware has changed over time with fixes and feature updates, so checking the release history on Flashforge’s wiki now and then is a better bet than assuming the machine shipped with everything it will ever need.
Re-run the ADM auto-leveling routine after the plate has been removed and reinstalled, after moving the printer to a new spot, or if first layers start looking uneven on one side of the bed. ADM handles the point-by-point calibration on its own, so this is a quick check rather than a manual tramming session, and it is worth doing any time the printer’s physical setup has changed. Flashforge’s maintenance documentation for the Adventurer 5M series extruder is the best reference for anything beyond these routine checks.
Not every problem calls for cleaning or lubrication. A nozzle that stays clogged after a wipe is often better handled with the general steps for clearing a clogged nozzle safely, and one that won’t clear at all points toward replacing the nozzle instead. If cleaning and a fresh ADM pass don’t settle an uneven first layer, work through the Adventurer 5M calibration routine before assuming a part has failed.