@creoleMalady You should be able to find the asked setting under the settings for the specific shared folder. Should be something about asynchronous write. If this is enabled things like what you experience can happen. Disable it and the problem should be gone. But there is one thing about that. While it is safer for the data, write speeds might go down a bit depending on your network.

@creoleMalady one more suggestion for the sake of an alternative solution. If you insist on managing multiple servers not in host (even though running them in a pool would equalize the CPU features to the oldest CPU available) you can use Cloudstack as a management platform to do the templates and networking for you. It dynamically transfers templates and assigns networks on demand on the hosts as you provision vms on them. The disadvantage is that you need to learn Cloudstack which can be much of an overhead by its own if you dont want to go too deep.

@creoleMalady This does not help you, but my setup works with MinIO S3 (current version minio_20220607003341.0.0_amd64.deb) and current XO commit a5e9f. I'm running XO commit 379e4 (June 2nd) and it has been working correctly with Wasabi. I updated XO to commit a5e9f (current master) on a second server and backup still works for me to MinIO.... Delta Backup as a full and as a delta with and without merge.

Sure, please keep us posted on your experiments If it's a bug, we'll have more info to be able to work on it!