REPRODUCIBILITY: 100%
OS VERSION: 5.2.0.15
HARDWARE: Jolla Phone (jp2601, “Jolla Phone 2026”), SoC MediaTek MT6858, kernel 6.12.38-4k
UI LANGUAGE: English
REGRESSION: Don’t know — likely long-standing; surfaced by IPv6-only mobile data
DESCRIPTION:
Preconditions: IPv6-only mobile data — the cellular connection gets only a global IPv6 address, no IPv4 (see thread 11917).
Steps to reproduce:
- On IPv6-only mobile data (WiFi off), browse / download a noticeable amount (~15 MiB).
- Check the mobile-data usage counter in Settings.
Actual result: the data-usage counter stays at 0 despite substantial traffic. Cross-checked against the kernel’s own interface byte counters (ip -s link show <cellular-iface>), which capture all traffic including IPv6:
RX ≈ 12.3 MiB TX ≈ 2.9 MiB (kernel counters, real traffic)
So ~15 MiB genuinely flowed, yet the UI counter reported 0 B. The counter appears to source its figure from an IPv4-only accounting path (or per-PDP RIL/modem byte counts that only tally an IPv4 context), so IPv6-only data is invisible to it.
Expected result: the mobile-data usage counter accounts IPv6 traffic on the cellular interface (as the kernel interface counters do).
Additional information: dangerous for users on metered/capped plans — they see zero usage while consuming their allowance. Part of a set of IPv6-only-mobile issues on the Jolla Phone 2026 (SFOS 5.2), filed separately — mobile data comes up IPv6-only (thread 11917); connmand SIGSEGV on WireGuard connect (thread 30643); WireGuard import truncates a bracketed IPv6 endpoint; and connman-vpn doesn’t install a peer’s AllowedIPs routes.