You’re getting complaints from friends, family and clients that your number is always unreachable or busy yet you have been staring at your phone all day, no calls. No airplane mode, no call barring, no call forwarding, no Do Not Disturb (DND), what could be wrong?
The source of this problem varies with device brand / model so lets look at a few cases.
Transsion (Tecno, Infinix & Itel)
The source of this issue might be call reject in smart panel. To open smart panel, navigate to Settings and type smart panel in the search bar. Select Smart panel from the result and toggle it on.
To open smart panel, simply swipe right from the left of your screen. You’ll notice that Call Reject is on. Turn off / disable it
For Dual 4G phones like the Xiaomi Redmi 9T, the problem might be the dual 4G settings. You might notice that you can only receive calls on a SIM when its set as mobile data. This is because the inactive SIM is unable to switch from 4G to 3G which is used for phone calls.
To fix this issue, you toggle off Dual 4G under Settings > SIM cards & mobile networks