DKIM and DMARC are probably the issue. A 7.7 out of 10 is not a great score. You should try to get that into the 9+ range if you don't want any email going to spam.
Talk to your hosting provider and do google searches on how to add DKIM and DMARC and SPF records if you haven't fixed those yet. Depending on the server it may be something you can easily configure or turn on in your server portal. Sometimes you can just use an authenticated email and send it through your regular SMTP server to improve spam scores.