Hello, I am Leonielhou, an Independent Advisor and a user like you, I am happy to help clarify any questions you may have.
You have tried changing the junk email filter?
It seems to be a system problem since it should not be penetrating into the inbox. it is better you contact Microsoft Support directly about this.
You can reach them out using this link:
(For Chat support) https://support.microsoft.com/contactus
and then choose Microsoft 365 and click for Home or Business. Type "Office" into the description box and choose any from the dropdown and click Get Help. Below the recommended articles, sign in using your Microsoft account to access their contact page