`fio` does not timeout even specified?

# fio --name=random-write --directory=/mnt/test/ --ioengine=posixaio --rw=randwrite -bs=4k --numjobs=1 --size=4g -iodepth=1 -runtime=600 --time_based --end_fsync=1
random-write: (g=0): rw=randwrite, bs=(R) 4096B-4096B, (W) 4096B-4096B, (T) 4096B-4096B, ioengine=posixaio, iodepth=1
fio-3.7
Starting 1 process
random-write: Laying out IO file (1 file / 4096MiB)
Jobs: 1 (f=1): [w(1)][100.0%][r=0KiB/s,w=0KiB/s][r=0,w=0 IOPS][eta 00m:00s]    

Any idea why it returned after 60 mins rather than 600 seconds that I set?

I checked dmesg, no error:

[Mon Mar  1 20:53:36 2021] XFS (sda2): Mounting V5 Filesystem
[Mon Mar  1 20:53:37 2021] XFS (sda2): Starting recovery (logdev: internal)
[Mon Mar  1 20:53:45 2021] XFS (sda2): Ending recovery (logdev: internal)

I ran the same command on another drive (a SSD instead) on the same box at the same time, and it finished on time and returned.

Thanks in advance!