Regression in 1.1.20: receiver-paired keyboard battery reads "Battery status unavailable" (mouse on the same Bolt receiver works)

Summary

After upgrading Solaar 1.1.19 → 1.1.20, my MX Mechanical keyboard's battery reads Battery status unavailable. in solaar show. My MX Master 3S mouse — paired through the same Bolt receiver and using the same UNIFIED BATTERY {1004} V3 feature — still reports correctly. Downgrading to 1.1.19 restores the keyboard reading. Both devices were unchanged across the upgrade (no re-pair, no firmware change).

The only battery-related change in the 1.1.20 changelog is #3217 ("Show offline status for receiver-paired device batteries", merged 2026-05-13), which touches exactly this code path, so I suspect it's the cause.

Steps to reproduce

1. Pair an MX Mechanical keyboard and an MX Master 3S mouse to a single Logi Bolt receiver (046d:c548).
2. Run solaar show on Solaar 1.1.20.

Expected

Both devices report a battery percentage (as they do on 1.1.19).

Actual

Solaar 1.1.20 — keyboard battery is unavailable, mouse is fine:

1: MX Mechanical
     7: UNIFIED BATTERY      {1004} V3
        Battery status unavailable.

2: MX Master 3S
     8: UNIFIED BATTERY      {1004} V3
        Battery: 65%, BatteryStatus.DISCHARGING.

(Reproduced on 3/3 consecutive solaar show runs, with the keyboard actively in use — not asleep.)

Solaar 1.1.19 — both report correctly:

1: MX Mechanical
     7: UNIFIED BATTERY      {1004} V3
        Battery: 75%, BatteryStatus.DISCHARGING.

2: MX Master 3S
     8: UNIFIED BATTERY      {1004} V3
        Battery: 65%, BatteryStatus.DISCHARGING.

Note: while on 1.1.20, the Solaar GUI still displayed a keyboard battery percentage (apparently from a cached battery notification), but solaar show and any consumer of the synchronous read returned "unavailable".

Environment

• Solaar: 1.1.20 (distribution package; Arch extra/solaar) — bisected against 1.1.19
• OS: CachyOS (Arch-based), kernel 7.1.2-2-cachyos
• Python: 3.14.6
• Receiver: Logi Bolt Receiver, USB 046d:c548
• Keyboard: MX Mechanical (codename MX MCHNCL, firmware RBK 71.02.B0019)
• Mouse: MX Master 3S (codename MX Master 3S, firmware RBM 22.02.B0009)

Suspected cause

#3217 — both devices are receiver-paired through the same Bolt receiver and use the same {1004} V3 feature, yet only the keyboard regresses, which points at how a device's online/battery state is evaluated for receiver-paired devices rather than at the battery feature itself.