Even if you can change the software settings, you cannot change the physical components to transmit on a different frequency. The OIP is such a simple and cheap device I doubt that the manufacturer will implement dual band components.
Might be simpler to just buy one that operates on the right freq.
I flashed it with Aercus firmware which is 433MHz and it is still on 915MHz greyed out so the receive chip must be 915MHz only and can not be changed.
It would cost more to send back than it is worth. So I might pull it apart and have a look. I might be able to swap out the chip.
Edit: I pulled it apart and it is just a modular chip on a pin header. Should be relatively easy to replace if I can get the correct 433MHz one. I might even just be able to replace the 433MHz crystal. You cant see it but it is the 2 pins on the right at the back in the pic.
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