Rule #1: If you run mods, you can't blame the developer for "bugs" unless you can prove that the mods are not causing / did not cause the "bugs".

Rule #2: Don't trust steam cloud save. That's just something you learn over time, and is not isolated to Valheim, but Irongate even felt the need to add this to their patch notes: "However, for this patch we do advise people to make backups of your saves, just in case."