I have the same issue and have had to deactivate All In One SEO.
Hi – I had the same issue – strangely, all emails sent by the system worked fine – I was using Post SMTP – only the WordPress generated reset password messages failed. I disabled All-in_One SEO and it worked immediately.
I am having the exact same problem. I have also been using this plugin for years with no problem but nothing works now.
Exactly the same problem on my site with the same plugin
