We have established a new shop system since May 3. For safety reasons, we could not take over saved password data.
For this reason, you have to enter your password again to log in to your customer account. This has nothing to do with the technical challenges of the new system, but is a normal safety step in this conversion process. So you don't have to worry.
As soon as you have entered the password, you can save it as usual. Then you don't have to enter it again.