How to solve the problem of positioning error and flashing red light?

You may try the three solutions below to fix this issue.

1. Check the mobile app: Go to printer settings and select Gap for Paper Tape.
2. Reset the printer and run paper learning. You can watch the video below to learn about the paper learning steps. 

3. Calibrate the sensor, then run paper learning again.
   Below are the detailed sensor calibration steps.

   Step 1: Power on the printer, open the cover, remove all label paper, then close the cover.
   Step 2: To calibrate the sensor, long press the print button on the top of the printer. Release it after hearing six beeps. Immediately long press the button again and release after another six beeps. The sensor calibration is complete.
   Step 3: Load the label paper. Long press the print button and release it after one beep. The printer will start paper learning.