Docomo: Some 4G Devices Unable to Make Calls or Use Data — 'Issue Due to 3G Sunset'

Since April 1 some 4G-capable devices cannot make voice calls or use data; the issue is attributed to device problems following the end of 3G (FOMA) service and a recovery date is unknown.

Affected models are P-smart Keitai (P-01J), AQUOS Keitai (SH-01J), and RakuRaku Phone (F-02J).

The issue is related to VoLTE, the LTE-based voice call method; after the 3G shutdown calls require VoLTE to be enabled.

Reported symptoms include loss of calls and data for some users, the VoLTE setting appearing grayed out and unchangeable, and data ceasing to work when VoLTE is turned off.

Docomo advises rebooting the device and reinserting the SIM, enabling 'calls over 4G' via Settings → Network & Internet → Mobile network, and visiting a nearby Docomo shop if the problem persists.