I bought one of these to control my garage port. There are many improvements in Gen4, and I will cover some of them in this mini review.

I have been using a fingerbot to control my garage port until now. That solution is not always the most reliable, so I searched for information on my port automation, the Dexxo Compact RTS to see if I could add a relay instead, and I could.

Looking in the manual, you can see the 4 numbered port.
Port 1 and port 3 can be used to control the port automation.
Port 1 and port 4 provides positive and negative 24V DC power if needed.

Looking at the Shelly product lineup, there is a match with the Shelly 1 Gen4. It can run on 24V DC and provides a potential-free dry contact to control the garage port.
The WiFi coverage isn’t the best where my garage automation is placed, so the Zigbee addition on new Gen4 devices is a very welcome feature.

I wired up the Shelly to garage port automation, and did a simple test, and it worked just fine. The Shelly 1 Gen4 act as a switch in the default configuration, and my port needs a button, so I tried changing the behavior in the web interface, but the Shelly kept working as a switch even though I changed it to button.
That’s no biggie, I can just use turn on/turn off every time I have to use it in Home Assistant, but it must be some kind of bug.

I connected the Shelly 1 Gen4 via WiFi first and firmware updated it. With the new firmware applied, I tried switching to Zigbee mode via the physical button on the device. I pressed the button 5 times, and nothing happened, I tried a lot of times, restarting the device and tried again, and again. I searched the internet and could see I was not alone with this issue, there is multiple complains about this problem online, but people seem to get it working if they tried enough. After spending 15 minutes I gave up, and was quite angry why Shelly would ship something like this to their customers. I looked in the web interface, and after I cleared my browser cache, and went into settings, there was a new button in the interface saying “Switch to Zigbee”. This will switch the device into Zigbee mode, and restart it.
After the restart, you need to connect the device to your Zigbee network. I tried using the physical button again, and with no luck again. So I went into the web interface, found the new Zigbee menu, and enabled Zigbee, and after that I could pair it with my network.

If you just got one of these devices and want to switch to Zigbee, and suggest you to it like this:
1. Connect via WiFi hotspot, and connect the device to your WiFi.
2. Firmware update your device to latest stable firmware. (It works in 1.7.1)
3. Clear your browser cache, and connect to the web interface again.
4. Go to settings, and use “Switch to Zigbee” menu to make the switch.
5. Open the web interface again, and go to Zigbee menu and enable Zigbee.
6. Allow new clients on your Zigbee Controller.
7. Open the web interface again, and go to Zigbee menu and “Start Pairing”.
Some settings are reset when you switch to Zigbee mode, but my WiFi settings where not, so it was quite easy to reconnect after each restart.
I left my Shelly on WiFi, even though I am using Zigbee to control it, but as far as I know, you can only firmware update the device via WiFi at this time. And if you need to make any configuration changes to the device, you still need WiFi, as only the switch is exposed to Home Assistant via Zigbee.
If you are wondering what is missing in Zigbee mode, it is Matter. You can still use the device via WiFi, but Matter wont be supported.

It looks like Zigbee is still in the early days on Shelly devices, but after initial connect and configuration, everything have been stable, and it have worked every time, and that is the most important.
I do think it’s very nice that Shelly have so many possible ways of connecting the gen4 devices, being both Matter (WiFi), Zigbee, and Bluetooth compliant is very unique, and means you can always change your mind later, or use it for another project.
I always disable all the communication protocols that I don’t use, and I suggest you do the same. It will lower the power usage, and it will make the device a lot safer to security vulnerabilities. If you leave the WiFi AP on, everybody can connect and control your device, so make sure to check the top right corner of the screen, where Shelly made a nice overview of communication protocols. (Zigbee is still missing)

I used to enable eco mode on my Shelly devices, but in the latest firmware I have seen huge delays with eco mode enabled, so I have disabled it again.

Conclusion:
Despite the problems with the physical button and Zigbee, and with the virtual switch that wont turn into a virtual button, I still think this is a very good product. Shelly provides concurrent firmware updates, so those smaller issues could be gone in a few months.
Shelly 1 Gen4 add Zigbee to an already good product. That improvement will make even more people buy the product, and I don’t think the buyers will be disappointed.