Comment by janekm

Something worth keeping in mind is that Chinese factories that makes things like IP cameras don't typically have their own (significant) R&D departments and instead work from examples provided by the makers of the chipsets. Sometimes there will be another company involved that provide an "IoT ecosystem" (Tuya is a major player here: https://www.tuya.com/solution/hardware/ip-camera ). So it's not necessarily surprising that the backend still works even if the manufacturer (Amazon brands are not typically the factory themselves, for practical reasons frequently changing "brand names" are used) is no longer present.