Duwi 05438 conflict?

Hello there,

I have two Duwi 05438 light switches outside. They worked both fine, untill last week. One of the two devices switches automacly off after approx 5 seconds.
When i turn on the off button on the switches off device, the other device, that was still on goes off.

Anyone an idea what settings i have to check to start fixing this problem:
Thank you

Interesting, I have similar issues, it switches on and randomly switches off