Multilingual plan configuration - workflow email translations doesn't work

Hi all,
I'm currently trying to make e-mail notifications from CB Subs multilingual.
(Joomla!3, CBSubs 4.8.0, System Default Language German)

CB Subs -> Plans -> Edit Subscription Plan x -> Tab 'Presentation':
All fields with a text editor seem to work as expected.
Example: 'Description of plan' - if I enter 'REG_CLUB_DESC' here, the translation with the key '<p>REG_CLUB_DESC</p>' takes effect.
This also works for all other workflow fields that use a text editor.

It doesn't seem to work for e-mail fields (without an editor).
I have tried all possible combinations. HTML mail/text mail with and without <p> tags.
The mails only ever contain the key, never the text.

The fields are specified as: 'language translations are supported'
Is there something special to bear in mind here, or is it a bug?

This applies to all workflow e-mail fields (subject and text):
Email on first activation, Email on pending first payment, Email at each manual renewal...

Those emails are passed through language API so it should work perfectly fine. Ensure all your languages are translating it though including the Default English language plugin. It should send in the language of the recipient.

My website has been multilingual for a long time without any issues. Only the mails from CB Subs are missing. I wanted to fix that now.

I did extensive tests again on a clone of my live site.

PROBLEM WORKFLOW MAILS

The following plan workflow emails work (subject and body):

• Email on pending first payment
• Email on pending payment of manual renewal

The following planned workflow emails do not work (neither subject nor body):

• Email on first activation
• Email at each manual renewal
• Email on expiration

Not tested:

• Email at each automatic renewal
• Email on cancellation by user

 NEW PROBLEM WITH MAILER

During my tests, I also encountered an even stranger problem with the mailer. I have a single mail rule there. See screenshot for how this mailer behaves.

The column L I added stands for the user's language settings. A dash means default.
Reminder: my default language is German, not English! Please also note the different result languages under the same conditions!

Furthermore, it seems that only the subject is translated, never the mail body, which always only contains the language key!

In the MySQL database, I saw in the 'j30_cbsubs_mailer_sentmails' table that the body looks like this in the mailer:<p><p>LANGUAGE_KEY<\p><\p>

I therefore also tried it with the complete string as the key, but that didn't change anything. The text was not translated.