I have checked the URL provided (https:// <my website> /index.php?option=com_easydiscuss&task=cron) and I noticed the following text:
Invalid address: (to):
This seems to indicate the destination email address set in EasyDiscuss is empty or incorrectly formatted.
Can you double check your configuration for this component via your Joomla admin panel?
I've checked my EasyDiscuss setup to the EasyDiscuss documentation and all seems ok.... and I've checked that filepath to PHPMailer.php is correct.
The changes I've made recently that may have caused this to stop working is moving from Joomla 3 to Joomla 4 - and changing to a new template in the process (T4 Framework from JoomlaArt)