Freron MailMate

I have the PGP tool suite installed for MacOS and the newest MailMate. When sending an encrypted email and opening it on the MailMate app it fails stating:

ENC_TO 65###9DDB83F4FF0 1 0
KEY_CONSIDERED AA5C3###C58E7D0431##71D93ED0B###52A64CD8 0
NO_SECKEY 6###49D###3F###0
BEGIN_DECRYPTION
DECRYPTION_FAILED
END_DECRYPTION

When trying to send an encrypted message with that same key it also fails with:

KEY_CONSIDERED AA5C3####58E7D###D871####D0B65B5###4CD8 0
KEY_CONSIDERED AA5C3####58E7D0###871####D0B65B5###4CD8 0
INV_RECP 10 AssociatedEmail@librem.one
FAILURE encrypt 53

Using Canary the same setup with iOS client and MacOS client works fine.

What am i doing wrong in MailMate. I created the plist file:

{ map = ( { address = "GoatWildernessCollectiv@librem.one"; serial = "AA5C ##### C58E ##### 31D8  71D9 #### B65B #### 4CD8"; }, ); }

So it looks like it is using the right key as desired to encrypt, but fails encrypting and decrypting :-/