Pixel 9a: System (BASE) runtime exceeds total screen time - seeking explanation

Rpa440

Device : Pixel 9a, fresh GrapheneOS install (January 2025)
SIM: New SIM, new carrier, new number
Setup: Multiple profiles, minimal apps, no Google Play Services
Observation:
Looking at battery statistics, I noticed a mathematical anomaly I cannot explain.
Current session (Saturday 20h00 - 20h29, ₃₀ min window):

Battery usage by system:

Mobile network: 55%
Camera: 32% (Total: less than 1 min)
Screen: 10% (Total: 13 min)
System (POWER_COM...): 2%
System (VIDEO): < 1% (Total: less than 1 min)
System (AUDIO): < 1% (Total: less than 1 min)
Always-on display: < 1%
System (SENSORS): < 1%
System (BASE): < 1% (Total: 29 min)

Thé math problem:

Screen time: 13 min
System (BASE) runtime: 29 min
Delta: 16 min of baseband activity with screen off and phone idle

Even assuming maximum parallel background processing during all screen-on time, BASE runtime should not exceed screen time by this margin. The baseband appears active during periods when the phone was completely unused.

Additional observation:
Battery statistics seem to reset/disappear within 2-8 hour windows rather than persisting until full charge cycle. Earlier today I observed similar anomalies (System AUDIO: 16 min, System VIDEO: 22 min with only 4 min screen time) but stats disappeared before I could document properly.
Questions:

Is there a legitimate explanation for BASE runtime exceeding screen time?
Known AOSP bug causing stats to reset frequently?
Any way to log/monitor baseband activity for analysis?

Looking for technical explanations, not reassurance.

Watermelon

Rpa440 There is another item type called “mobile network” — presumably, it represents the baseband, and what you're referring to represents base components like CPU and RAM.

Your device is protected even if the baseband is compromised:
https://grapheneos.org/faq#baseband-isolation

You can reduce the chance of the baseband being compromised:
https://grapheneos.org/usage#lte-only-mode

See my tutorial for increasing security on GrapheneOS from the default:
https://discuss.grapheneos.org/d/28682-maximum-security-and-anonymity/4

Even if it does/did represent the baseband, I don't see what's the reason to freak out. Many background tasks that your phone does can be online tasks.