Adobe Acrobat Reader cannot open encrypted PDF created with SodaPDF using 256bit AES encryption

Hi, 

I have a customer whom creates encypted PDF files and encrypts them in SodaPDF (the default is 256bit AES encryption). When attempting to open the file with supplied/correct password Acrobat reader states it cannot decrypt the file.

I can replicate the issue myself and have created a test file. The files opens in SodaPDF (duh) and also SumatraPDF fine but not Acrobat Reader.

Changing the encryption in SodaPDF to 128bit AES works fine in all apps (sumatra, acrobat etc)

Any reason why this is happening?

Test file attached, password is Password1234

Many thanks,