Emails sent with Sendgrid go to spam on Multisite subsites

I use Sendgrid for SMTP.

It works for all top level sites.

The problem arises on multisite. It does work on the current_root_domain. However, all of the subsites (subdomains) send the emails to the spam box on gmail.

I have added the SPF record for sendgrid on all of the subdomains.

I’ve tried setting the “FROM” email in gravity forms to the current_root_domain, but it still goes to spam.

Any ideas?

Thanks in advance!

Has anyone run into this issue?