Hello there,
As you facing this issue only with specific domains I would suggest you check the whitelist or your spam folder.
This can also occur if one of the following is true:
The domain has to replicate to all Microsoft Exchange Online servers. This could take up to one hour.
The appropriate MX record doesn't exist or has to replicate to all applicable Domain Name System (DNS) servers around the world. This could take up to 72 hours.
Email messages aren't received for a new domain that you add in the Microsoft 365 portal https://learn.microsoft.com/en-us/exchange/troubleshoot/email-delivery/emails-not-received-for-new-domain
Hope this resolves your Query !!
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