Hi @Adak ,
Please take a look at the following document and see if these methods could work for you:
https://support.microsoft.com/en-us/office/guest-doesn-t-receive-group-email-conversations-b9891873-c33c-415a-8751-66a64d17f06c
And like I said, you may use your own organization account on Teams for desktop and use the guest account on Teams for web to receive messages at the same time. It would be better than switching the account type:)
Best regards,
Lou