WebSerial connection not working with Ender 3 v2

[nkymut]

Issue Description

The USB connection between p5.fab and Ender 3 v2 is not working properly. While initial connection is successful, the printer becomes unresponsive after first commands.

Observed Behavior

1. Initial connection works:

   • Printer connects successfully via USB
   • Auto-home command (G28) executes correctly
   • Temperature commands (M104/M140) work initially

2. Problems after initial commands:

   • Console shows "print finished!" prematurely
   • Printer stops responding to new commands
   • Position reporting (M114) stops working

3. When the same G-code commands are sent through a serial terminal, they work perfectly
   - This suggests the issue is with p5.fab's serial communication, not the G-code generation

Steps to Reproduce

1. Using control-panel example:
   • Connect to printer
   • Run auto-home command
   • Try to use any movement controls
     -> Printer immediately shows "print finished!" and stops responding

Environment

• Printer: Ender 3 v2
• OS: macOS Sonoma version 14.4.1
• Browser: Chrome Version 131.0.6778.87 (Official Build) (x86_64)

Additional Notes

• Serial connection remains active (no disconnect errors)
• Need to refresh page to restore functionality
• Only first command in sequence executes successfully

/label bug