Salesforce Backups - Increased Warning/Error Rate

Salesforce has started the rollout of their fix plan on Sandboxes and some Production orgs.
We are monitoring to see the backups are error free on these objects as a result

Our team is working with Partner Support from Salesforce to promote a fix for the Salesforce Known Issue ( https://trailblazer.salesforce.com/issues_view?title=querying-on-feed-objects-with-encrypt-chatter-enabled-throws-error-should-not-be-here-platform-encryption-dao-encryptablefielddefinitionproviderimpl&Id=a1p4V000002nNdr).

Currently, it shows that Salesforce is scheduled to have the fix in Spring’22 Patch 12.0
Here is what we know so far and expect if the org has enabled a platform encryption policy on Chatter.

1. The Feed Items object is getting backed up successfully; this is the main object used for Restore and gets associated with the parent object if chatter was used on the record. Our tests show that this object is not affected.
2. Individual object Feeds receive an error, and services will show a yellow triangle warning in the weekly report, along with object errors in the backup history and a yellow exclamation mark in the service dashboard. This means these objects are not getting backed up and will be missing from the data set.
3. The service will experience an increased backup duration and API usage, due to the retry mechanism on the feeds objects.

Until the Salesforce patch is deployed, you may select the Service-->Options-->Exclude Feed Items in your Ownbackup service to suppress the error messages and maintain nominal backup time by avoiding the backup of those individual Feed objects. The Feed Items object itself will continue to backup and be restorable with such configuration.

We will continue to update this incident as new information makes itself available.

The issue is related to this known issue posted by Salesforce- https://trailblazer.salesforce.com/issues_view?title=querying-on-feed-objects-with-encrypt-chatter-enabled-throws-error-should-not-be-here-platform-encryption-dao-encryptablefielddefinitionproviderimpl&Id=a1p4V000002nNdr.
We are working with Salesforce for resolution as the workaround provided cannot be applied at this time while ensuring a 100% integral backup, and we are treating this is as our top priority.

The issue is related to this SF known issue- https://trailblazer.salesforce.com/issues_view?title=querying-on-feed-objects-with-encrypt-chatter-enabled-throws-error-should-not-be-here-platform-encryption-dao-encryptablefielddefinitionproviderimpl&Id=a1p4V000002nNdr

SF confirmed this is an internal issue they are facing with.
SF backend teams are working on investigating this and providing a solution.
We will update ASAP.

The backup warnings and errors are related to FeedItems and Feed objects in general.
We have contacted Salesforce Partner support to investigate the issue.
This impacts production & sandbox services.

We are seeing an increase in backup warnings and errors for Salesforce Sandbox backup services.
We currently do not see an impact on Salesforce Production backup services.
We are investigating the issue and will provide an update as soon as more information becomes available.