Updraft BackUp Scheduled Task Warning

Hi
I am using the free version of the Updraft Backup/Restore plugin and I am getting the following warning on several sites:

Warning: WordPress has a number (36) of scheduled tasks which are overdue. Unless this is a development site, this means that the scheduler in your WordPress install is not working properly.

I have read your documentation and have tried the following remedies:
1. Cleared cache
2. Verified WP time zone settings
3. Checked wp_config file for any instance of disabled wp_cron (nothing was found)
4. Checked wp_config to see/increase memory limit (nothing was found)
5. Attempted to schedule a post, the schedule was missed
6. Disabled the Updraft plugin and attempted to schedule a post, the schedule was still missed
7. Visited pages on my site to stimulate traffic
8. Contacted my host, who told me I needed to contact your support

None of the above has helped the situation, any suggestions would be helpful. I’m getting this error on my site, as well as some client sites, which makes me very nervous.

Thank you