Sorry for posting again, I am unable to edit my post.
I’d like to add that with WP_DEBUG set to true, and WP_DEBUG_LOG set to true, nothing is written to the wp-content/debug.log file.
Update solved problem
So it seems the problem was that after migrating to a self hosted solution, there was no email set up in the back end, so after installing the plugin Post SMTP it is working again. Link: https://www.ads-software.com/plugins/post-smtp/