Note what the ACE Pro or Kobra 3 display actually says, and whether the failure happened mid color-swap or during a plain single-material print. That distinction narrows down the cause fast. Anycubic’s ACE Pro use notes on its wiki cover model-specific behavior in more depth than general forum advice, so check them before assuming a fault.
If parts still come out damp or brittle after drying, check the material first. PLA, PETG, TPU and PVB dry well with the ACE Pro’s two 200W PTC heaters over cycles up to 24 hours. ASA, ABS, PET, PA, PC, PP, BVOH, POM, HIPS and fiber-filled filaments are listed as compatible but not optimal for drying, so a completed cycle on those materials may still leave weaker results than PLA or PETG would show.
For tangles or clogs, the ACE Pro’s mechanical buffer system should detect the problem and pause the print rather than force filament through. Open the affected spool bay, unwind any overlapping wraps on the spool, and check the tube for kinks before resuming. Repeatedly restarting the feed against a jam risks grinding the filament or straining the feeder motor, so stop and clear it properly instead.
Wrong material or color readings usually trace back to a spool without Anycubic’s intelligent identification. Without that tag, the ACE Pro cannot detect either value, and every slot needs material and color entered by hand before slicing. A mismatched manual entry is a common cause of wrong-temperature prints, not a sign the hub is broken.
Auto-replenishment only triggers between two consecutive spools of the same color, so a mid-print switch to a different color has to be set up in the slicer, not left for the ACE Pro to figure out. TPU cannot run through the ACE Pro at all; feed it directly into the Kobra 3 as a single-color job. For heater faults, wiring issues or failures that persist after these checks, use Anycubic’s official ACE Pro documentation and support channels rather than opening the unit yourself.
Many of these issues trace back to setup rather than a fault in the hub itself, so it is worth rechecking the ACE Pro setup steps, especially tube routing and spool seating, before assuming a part has failed. A hub that keeps jamming or misreading filament is also a good prompt to work through the Kobra 3 regular maintenance schedule, since a clean feed path on the printer side reduces the chance of a repeat problem.