User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:106.0) Gecko/20100101 Firefox/106.0

Steps to reproduce:

Register 2 Email adresses, supply one of them with an S/MIME certificate for encryption and signing, and the other one with an OpenPGP key.
Select the inbox of either of the two Email adresses and click on the button to write a new Email.

Actual results:

For both accounts, OpenPGP is selected as the default encryption method.

Expected results:

For the accout for which only the S/MIME key was provided, S/MIME should be selected as encryption method.

Notice that Settings/Account-Settings/End-to-end-Encryption/Preferred Encryption technology is grayed out for the S/MIME account.

If I create an OpenPGP key for the S/MIME account, then "Settings/Account-Settings/End-to-end-Encryption/Preferred Encryption" is no longer grayed out and I can select S/MIME as preferred encryption method and then the Defaults in the New-Mail windows are as expected. However, this workaround is quite a hassle.

xref/dupe bug 1796781

Even if PGP and S/MIME certs are installed, the account option to prefer S/MIME is ignored. PGP is always default unfortunately. Bug is in 102.7.2 still and I agree the workaround is a nightmare as I use encryption by default and need to change this with every email (for several month now).