Some of you also share the enthusiasm with me regarding Shelly – the others cannot be helped 😉
Here are the stats for 2024/2025 that I created for the Sensors from 2020 onwards – hope this helps some folks. If you need more specific info just reach out to me 🙂

Shelly 1 PM (Gen1):
Installed Sensors in 2020: 217
Defective Sensors until 12/2021: 7
Defective Sensors until 12/2022: 34
Defective Sensors until 05/2025: 162
+ Device not responding anymore at all
+ Device making a very high pitched sound, seem to still flip an internal switch but output no more power
+ Device is unable to save any settings, is in AP mode forever
Overall-Failrate: 74,65% –> For the long-term not reliable

Shelly 2.5 (Roller-Shutter-Mode), (Gen1):
Installed Sensors in 2020: 11
Defective Sensors until 12/2021: 5
Defective Sensors until 05/2025: 11
+ Device not responding anymore at all
+ Device is unable to save any settings, is in AP mode forever
+ Device likes to randomly “play” with the shutter, making me shit my pants every time
Failrate: 100% –> Was not reliable at all and have been replaced with Gen2

Shelly Plug-S (Gen1):
Installed Sensors in 2020: 15
Defective Sensors until 12/2021: 1
Defective Sensors until 05/2025: 1
+ Device sounds like its working and switching the load, but does not (dead)
Failrate: 6,67% –> So far they are super reliable!

Shelly RGBW2:
Installed Sensors in 2020: 3, in 2021: 7, in 2025: 13
Defective Sensors until 12/2021: 0
Defective Sensors until 05/2025: 0
Failrate: 0% –> So far they are super reliable!

Shelly Door/Window 2:
Installed Sensors until in 2020: 7
Defective Sensors until 12/2021: 1
Battery drains 25% per Month (Vibration and Tilt activated)
Failrate: 14,28% –> Still all replaced, as in 2025 a battery life of 2-3 months is not acceptable anymore.

Shelly Plus 1 PM (Gen2):
Installed Sensors in 2023: 13, in 2024: 52, in 2025: 2
Defective Sensors until 05/2025: 0
Failrate: 0%

Shelly Plus 1 PM (Gen3):
Installed Sensors in 2025: 2
Defective Sensors until 05/2025: 0
Failrate: 0%

Shelly Plus 1 PM (Gen4):
Installed Sensors in 2025: 2
Defective Sensors until 05/2025: 0
Failrate: 0%