Huawei
Set Preferred Network Type (2G/3G/LTE) auf Huawei
Your Huawei phone negotiates a mobile network standard for every SIM card separately. When the preferred network type is locked to LTE only, a weak 4G signal can drop the connection completely instead of falling back to a slower but stable 3G link.
The Preferred network type option controls this behavior per SIM. Forcing 3G or 2G stops the modem from repeatedly searching for LTE, which often fixes call drops, stalled data or a signal that keeps flickering between bars.
To change it, follow this path:
Open the settings ➔ Tap on Mobile network ➔ Tap on Mobile data ➔ Tap on Preferred network type ➔ Choose between one of the given options
Switching to 3G lowers maximum download speed but usually gives a more consistent connection in areas with poor LTE coverage. If data stays unreliable even on 3G, check general signal strength or contact your carrier instead of forcing 2G, since 2G only supports calls and very basic data.
Switch back to LTE, or to Automatic if that option is offered, once you leave the weak-coverage area. Otherwise browsing and downloads stay noticeably slower than necessary.