You didn’t state that you dried your filament. Try that first but before you do, it’s important to weigh the filament before and after drying to ensure that moisture was removed and how much. Otherwise you’ll be guess at the root cause.
Alternatively, try cutting the model into one smaller section and start testing different temperature settings. This has been discussed in this post on PETG.
This kind of stringing is an indication of incorrect temperatures. That can be cause by the following:
- Moist filament
- Incorrect temperature readings from the hotend that may be caused by faulty thermistor readings. The possible remedies are:
- First, try to reseat the thermistor connector
- Second, inspect the thermal grease underneath the silicone cover and thermistor.
- Deteriorating silicone sock whereby the hotend is not reaching correct temps. These must be replaced periodically. Inspect yours and make sure it isn’t damaged.
- Verify that your filament is calibrated. Don’t trust the Bambu defaults. Perform manual calibration. Even if you did it before, do it again.
- Check to make sure that your chamber fan is off.
- Check the temp of your chamber using a thermometer. Ensure that the door is closed to the printer and that a draft isn’t prematurely cooling the part.
The other diagnostic step that you may try is to rotate the model on the bed to see if there problem moves. If it is, then that could be an indication of uneven airflow over the part possibly by an open door or maybe air conditioning blowing on the chamber.