Since early 2021, requires full domain alignment across the SPF, DKIM, and DNS. If the domain from which an email is sent doesn't adhere to that, it won't be accepted.

Since Groove doesn't have fixed IPs from which emails are sent, to fix this you'll need to set up a custom SMTP server and configure your inbox to use that.

For the rules your SMTP server will need to adhere to, refer to the following external article: How to Meet the New Email Delivery Requirements.