I'm creating a separate entry for this issue because it seems to be widespread. Some "solutions" have been posted in [https://www.homekit.blog.com/r/HomeKit/comments/jbvbhz/meross_smart_plug_firmware_update_process_with/](https://www.homekit.blog.com/r/HomeKit/comments/jbvbhz/meross_smart_plug_firmware_update_process_with/) but for me none of them worked.

Here are the facts:
Setting up HomeKit with Meross products is often easy, but you need to access them in the Meross app to find special settings or update your product firmware. On iOS, this only works after you've added them to the HomeKit and then accessed the Meross app by pressing the + sign, and the app should give you available devices to add.

This worked for the first two Meross products (external and internal plug), but one of them was not accessible from the Meross application after some time, it even worked well with HomeKit. At the same time, I found out that I can't add other Meross products to the Meross app. It all works with HomeKit, but the Meross app doesn't see the new products. In addition, I tried to reconnect the plug that does not work in the application and is no longer found. Only the first external plug exists and still works.

I tried different solutions, always making sure I was on the same 2.4 GHz network (UniFi setup with lots of smarthome products that work well). I tried to delete the application, to turn on the devices, waiting up to 10 minutes and more. Meross support is no longer helpful, the only repetition of what I told them I had already done.