Hopefully you have access to a steam deck, but if not I've listed major details of my install that may or may not be bug related.
GUI: KDE/plasma 6
Window system: X11
Steam installed via pacman (NOT flatpak)

To save you a lot of time installing, run "archinstall" unless you want to do the long ...

If your windows install is receiving a conflict message, that means that the fresh install did wipe the blueprints file. That is the bug. Why is it wiping the cloud blueprints after doing a cloud sync when launching it first-time?
My windows and other linux install with the existing blueprints do ...

Reproduction steps:
-Have an existing blueprint saved in the steam cloud sync
-Have an existing save game also in the cloud
-Have a new device that hasn't had factorio before (in my case, a brand new steam deck.)

-Check your cloud storage in steam with a browser (https://store.steampowered.com ...

Hello,

Bit of a necro for this rather upsetting bug. It is still occuring now, as of [1.1.91].

This has happened to me before (in ver 1.0) but I lacked info to update this bug report.
In the unreported instance I had dualbooted from win10 to linux and had my blueprints removed.
It happens when ...