failed systemd units on new install of carbonio ce - implications and how do I troubleshoot?

script-based single server installation of carbiono ce 26.03.0 on Ubundtu server 24.04.4

I have a basically unconfigured carbonio server - the password for zextras has been changed, and I've added a test user (to determine where I need to provision storage for the the mail I will be migrating here).  In the rehersals/testing, e.g. shutting down all the carbonio services cleanly  I have discovered that after some amount of idle time and/or light testing (sending email between two on-host users) that service units (not sure of the correct jargon) have failed:

Get the list of all Carbonio services

systemctl list-unit-files

systemctl status
● mail.domain.com
   State: degraded
● mail.doamin.com
   State: degraded
   Units: 556 loaded (incl. loaded aliases)
    Jobs: 0 queued
  Failed: 2 units
   Since: Tue 2026-04-21 23:19:36 PDT; 1 day 15h ago
 systemd: 255.4-1ubuntu8.15

so - what has failed?

~# systemctl list-units --failed
   UNIT                             LOAD   ACTIVE SUB    DESCRIPTION                   
   ● carbonio-docs-editor.service     loaded failed failed Carbonio Docs Server
   ● carbonio-preview-sidecar.service loaded failed failed Carbonio Preview sidecar proxy
 
   Legend: LOAD   → Reflects whether the unit definition was properly loaded.
           ACTIVE → The high-level unit activation state, i.e. generalization of SUB.
           SUB    → The low-level unit activation state, values depend on unit type.
  
  2 loaded units listed.

anybody with any knowledge about what this means  for ongoing operations, and what, if anything I can do about it -- please weigh in.