It is reported that the company is already studying the problem and trying to fix it, but so far it is not known what went wrong.
We temporarily turned off cloud storage in Hyper Light Drifter, we already understand the reasons that lead to the departure of the Epic Games launcher. We are actively researching and working on the fix.
It is also reported that the local save will not be affected due to a bug. In the comments on tweet, some users note that other games with cloud saves are experiencing such problems.