It gets stuck sometimes with the on/off, sometimes the on sends voltage to L1 and other times to L2 (maybe I did something wrong)

I have one in the warehouse to control ventilation (Automation: Apple HomeKit in combination with Meross MS100FHHK sensor to work the ventilation and dehumidifier)
And another one to control the lighting. (Automation: Apple HomeKit when I turn on the lights, the ventilation turns on)

It connects very easily to Apple HomeKit without the application.
Through the application, I can control the LED to turn on when the switch is on and turn off when it is off (it serves me with ventilation) you can have the LED active when the switch is off to see where the button is when it is dark ;)

The photo with the round button is wrong, both that I received had a long button (like the American ones)
It would be very nice for the LED to illuminate the entire button.

Unfortunately, it constantly disconnects from the HomeKit setting of the house, which makes its purchase useless.

It requires reconfiguration once a week. And I have three of them.

And I have at least 60 other HomeKit accessories that do not present any problem to me.

First and foremost: this switch is ALLER-RETOUR (two-way). I had researched it on their website and its purchase confirmed it for me. In an aller-retour circuit, you only need to replace one switch with this one and the entire circuit functions normally. The MSS510X model is the non-aller-retour and this one, the MSS550X, is the aller-retour.

Also:
Easy setup on HomeKit, worked immediately.
Immediate response to commands from the mobile.

Note: like all smart switches, it does not have the classic "ears" to secure it in the wall box and it is secured with screws in the corresponding slots that the "new type" boxes have. If you have such boxes, all is well.
[EASY HACK]: Otherwise, you can drill 2 holes with a 6mm drill bit inside the box, at the middle height, one on the far left and the other on the far right, and of course, insert a wall plug in each hole. Then you can secure the switch with common (chipboard) screws 7cm long (70x3.5), and it will definitely hold much better than what I have seen with the "new type" switch boxes.

EDIT 3/7/2023

THE ONLY DOWNSIDE:
I asked Meross about the possibility of releasing this switch in a version with two buttons, and they replied that they "do not consider such a possibility because they do not see any demand in the market" ?‍♂️?‍♂️?‍♂️. Whatever you say, guys...

With a little searching on AliExpress, however, you can find switches that support HomeKit and are double or triple, and they look very similar to this one. I have ordered many of them, they all work fine, but they are not aller-retour. So in my house, I installed Meross switches where I wanted aller-retour and Chinese switches where I didn't, and I managed just fine without having to resort to solutions like Aqara (as I'm not a big fan of anything that requires a hub in general) or Legrand to save money!

The most economical solution to integrate a Homekit light fixture that does not have the ability to change its bulb (e.g. closed LED). It requires a neutral wire, which is usually not present in lighting switches in Greece, so if you have a socket above or below the switch and they are connected through a channel, you will be able to easily pull a neutral wire to the switch. Otherwise, it requires effort from the nearest socket or visible channel on the wall.

I liked the option to set a timer through the Meross app to automatically turn off after X minutes.

As for the negatives, it takes some getting used to the way you use the switch because the touch area is only on the power symbol in the center, so it is more practical to use your entire palm for contact rather than trying to find the center with your finger.