OJS not sending emails to reviewers

Our OJS is not sending email requests to potential reviewers. This is leading to major delays in the processing of manuscripts.
Other email channels like notification of new submissions and editorial decisions are working fine. Only the reviewers are not getting the email notifications from OJS. The activity log does not show any email being sent to the reviewers.
We are using OJS
Looking forward to support to resolve this issue.
EES Office


Can you please confirm that the email templates for reviewers (like review request, review request oneclick, etc) are all enabled and populated? A common problem here occurs if an editor enables “one click reviews” but forgets to also enable the email templates associated with that. No emails are sent in that case.