Bug (?): Setting a master password only encrypts folder with AES, files encrypted with AZE

Describe the bug
As the title says, when setting a master password to encrypt and then select a folder folder to encrypt, choosing AES, it will encrypt the files with AZE, not AES.
Decryption, then fails.

Encryption works fine if I individually encrypt folders, without setting a master password.

To Reproduce
Steps to reproduce the behavior:

1. Go to 'Settings'
2. Click on 'Security'
3. Set 'Master Password'
4. Create a test folder
5. Create a test file inside that folder
6. Encrypt the folder with AES

Expected behavior
File should be encrypted with AES, not AZE.

Screenshots
If applicable, add screenshots to help explain your problem.

Smartphone (please complete the following information):

• Device: Alcatel 1C
• OS: Android 8.1
• Rooted: No
• Version: 3.8.4 downloaded from Github.

Additional context
Allow me to also question if it's normal that the master password is suppose to be visible, when going to Settings > Security > Master Password?
Shouldn't be hidden?

Start in Settings > Security > Master Password and reproduce the issue by setting a master password, creating a folder and file, then encrypting the folder with AES. Check why the files are encrypted with AZE and why decryption fails; also verify the reported master-password visibility. Done means folder encryption respects the selected AES option and the behavior is covered by a regression test.