updating storage.cfg not working on 7.4. Potential bug?

AS I wrote, it just does not work with timeo, setting async does not work either...
Yes, I saw what you wrote and tried it with PVE CLI commands to avoid ambiguity of mis-edit. I pasted the commands I used for reproduction, whereas we still dont know if you were properly changing the file (no offence meant).
I also retried with V4 and my results were the same.

Please take a look at the commands I used and retry your experiment using them on a clean system. If you still can reproduce the problem, report back, including full PVE versioning.

good luck


Blockbridge : Ultra low latency all-NVME shared storage for Proxmox - https://www.blockbridge.com/proxmox