I have seen several issues relating to this. Recently (since the 10th of December), I have not been able to complete a full backup. I haven’t changed anything on my end for my two sites https://constructionlawva.com and https://christopherhill-law.com. I am using the latest updraft plus premium and have tried uninstalling and reinstalling, changing my cloud provider (same issues with Google Drive, Onedrive and Backblaze), and backups that used to take minutes now take hours. The only backup that worked (once) was one that was done after updating a theme. I started a full backup on each site around 10AM est this morning and at close to 3 PM still not complete and constantly stopping due to errors. This seems to be a problem for many.
I use hostgator but have changed nothing aside from updating the plugin.