Multi-switch device update failed: Cannot read properties of undefined (reading ‘switch’)
Hi, I have been using a 3-channel Sonoff switch with Homebridge eWeLink for a long time. However, I encountered a bug when turning on the 2nd channel. The 1st channel turns on for a second and then turns off again. The following error appears in the logs:

`[08/02/2025, 03:32:28] [eWeLink] [Salon] device update failed as Cannot read properties of undefined (reading 'switch') at default.externalUpdate (file:///var/lib/homebridge/node_modules/@homebridge-plugins/homebridge-ewelink/lib/device/switch-multi.js:331:66).`

Steps to Reproduce the Issue
	1.	Turn on the 2nd channel of the multi-switch.
	2.	The 1st channel automatically turns on and off in 1 second.
	3.	The error appears in the Homebridge logs.

Ewelink Version:  v12.3.3
Node.js Version: v22.13.1
Homebrigde Version: 1.8.5
System: Raspberry Pi
