This issue occurs when conflict module (8.x-2.0-alpha2) is enabled (on Drupal 9.1.14). When a poll has been translated, trying to edit and save the poll gives an error:
Error: Call to undefined method Drupal\poll\Entity\Poll::getChangedTime() in Drupal\conflict\Entity\ContentEntityConflictHandler->autoMergeNonEditedTranslations() (line 399 of /nrc/apps/www/myzone/web/modules/contrib/conflict/src/Entity/ContentEntityConflictHandler.php)
Enable conflict module.
Create a poll.
Translate the poll.
Edit the original poll (or its translation).
Make a change and attempt to save.
Poll entity class needs updating to support and/or not break when conflict code runs.
Postponed
1.0
User interface
Not all content is available!
It's likely this issue predates Contrib.social: some issue and comment data are missing.
Is this still relevant? How many poll users use also "conflict" module?
The MR is a blind re-roll without reading through the issue what needs to be actually done.
I'm also still not sure if we need this, maybe it has already been fixed? I guess this can be manually tested (without the patch) to see if there is a conflict with the conflict module.