I tried the plugin also on an 2nd domain and get the same result
Both stuck at 17%
Initializing…
Creating a job to start Backup
I checked the scheduled actions and could not find any related to the plugin
The 2nd domain is not even active and does not have plugins installed except for maintenance plugin.
Some site health info
A scheduled event has failed
The scheduled event, action_scheduler_run_queue, failed to run. Your site still works, but this may indicate that scheduling posts or automated updates may not work as intended.
The REST API encountered an unexpected result
The REST API is one way that WordPress and other applications communicate with the server. For example, the block editor screen relies on the REST API to display and save your posts and pages.
When testing the REST API, an unexpected result was returned:
REST API Endpoint: https://DOMAIN.com/TEST/wp-json/wp/v2/types/post?context=edit
REST API Response: (403) Forbidden
Your site could not complete a loopback request
Loopback requests are used to run scheduled events, and are also used by the built-in editors for themes and plugins to verify code stability.
The loopback request returned an unexpected http status code, 403, it was not possible to determine if this will prevent features from working as expected.
Hope this helps to fix the issue
Kind regards