Hello Diz1234,
I do not have any remote cameras myself so this is only a guess. With the iPhone 12 line being built for 5G I am wondering if your cellular data settings are causing this. I know you said the settings were the same but I am not sure what all settings you checked.
These can be found in the Settings App > Cellular > Cellular Data Options.
View or change cellular data settings on iPhone - Apple Support
I feel the below section may be the most relevant.
"Depending on your iPhone model, carrier, and region, the following options may be available:
- Turn Voice Roaming on or off: (CDMA) Turn Voice Roaming off to avoid charges from using other carrier’s networks. When your carrier’s network isn’t available, iPhone won’t have cellular (data or voice) service.
- Enable or disable 4G/LTE: Using 4G or LTE loads internet data faster in some cases but may decrease battery performance. There may be options for turning off 4G/LTE or for selecting Voice & Data (VoLTE) or Data Only.
On iPhone 12 models, you can do the following:
- Enable Smart Data mode to optimize battery life: Tap Voice & Data, then choose 5G Auto. In this mode, your iPhone automatically switches to LTE when 5G speeds don’t provide noticeably better performance.
- Use higher-quality video and FaceTime HD on 5G networks: Tap Data Mode, then choose Allow More Data on 5G."
I hope this is helpful,
