Deleting an active sieve script leaves sieve unfunctional

Dear devs,

I noticed this using Dovecot 2.3.7.2, set up on a newly created Ubuntu 20.04 server.

If I delete a sieve script via KMail's managesieve interface, and the script is active, it leaves sieve unfunctional afterwards.

What's happening is this:

Dovecot creates a USER.sieve script containing all active scripts, e. g.:

require ["include"];

include :personal "some-script";
include :personal "some-other-script";

Now if I delete "some-script", it's actually deleted, but USER.sieve is not updated (and still contains 'include :personal "some-script";').

So next time an email is filtered, this happens:

mail log:

Jul  5 15:20:01 server dovecot: lda(user@domain)<123456>
<xxxxxxxxxxxxxxxxxxxxxx>: sieve: Failed to compile script 
`/srv/sieve/user@domain/active-script.sieve' (view user logfile 
`/srv/sieve/user@domain/active-script.sieve.log' for more information)

active-script.sieve.log:

sieve: info: started log at Jul 05 14:57:54.
USER: line 12: error: included personal script 'some_script' does not
    exist.
USER: error: validation failed.

So, to avoid this, one has to FIRST deactivate the respectice script, so that USER.sieve is updated and THEN delete the script. Or to manually fix USER.sieve on the server, which is surely not what's intended.

So the question is now: Is this a KMail bug, a Doveceot bug, or is the server misconfigured?!

Thanks for all help!

Cheers, Tobias