The problem is you generated a new APP_KEY, then if you try to decrypt the old encrypted data it will show the
DecryptException: The MAC is invalid.
If you want to decrypt the old data you need to restore your old APP_KEY.
After realizing that, now, adding a new problem there, if you stored new data with another APP_KEY or another encryption method you have a problem on the data because they are mixed on the table.
In case you don’t know when do you started with the new encrypt method or differentiate the new encrypted entries, the fastest solution would be reset all the passwords with the new encrypt method.
You can learn more about how Laravel encryption works on the official Laravel docs.