Container terminated mid-processing after ~8-10 minutes of active work

Description

Running FFmpeg video processing in a Cloudflare Container. Works perfectly for smaller videos.
When processing longer videos, the container receives SIGTERM and exits after ~8-10 minutes of active work, regardless of job progress.

Logs

frame= 2250 fps= 48 time=00:31:32.00 ... # Actively processing
Received SIGTERM signal
Process exited with code -1

Job was 52% complete when terminated. FFmpeg was actively running — not idle.

Questions

1. Is there an undocumented maximum runtime for active containers?
2. Are containers terminated during host server restarts?
3. Does renewActivityTimeout() help here?
4. Any recommended workaround for long-running jobs?