Backblaze cloud backup fails when run automatically (exit code 5)

Hello, I have a cloud sync task set-up to backup my ssd pool to backblaze every night.
Lately it seems to fail with this error message:

[EFAULT] Checks:            260664 / 260664, 100%
Transferred:          152 / 152, 100%
Elapsed time:     18m41.8s

2025/06/24 04:18:44 Failed to sync: Post "https://pod-031-2029-11.backblaze.com/b2api/v1/b2_upload_file/2a5e01ff3c3924a69f5c051b/c003_v0312029_t0033": net/http: HTTP/1.x transport connection broken: http: ContentLength=29516301 with Body length 29562851
rclone failed with exit code 5

When I start it manually over the web interface the problem doesn’t occur and it runs through without any problem.
I am running TrueNAS CE (Scale) 25.04.1 and the SMART stats of the SSD don’t indicate any error.