This issue can occur when the care worker has two accounts set up for them, one active and one inactive. The inactive account may still have ties to CM Mobile, causing the personal messages to go to that account, instead of the active account.
This is because the inactive account was set up before the new account, so takes preference when receiving the messages if both accounts are linked to the same care worker record.
To resolve this, remove the CM Mobile application from both accounts for the care worker, and re-configure CM Mobile on the active account. This will remove the link to the old inactive account ensuring the messages are only sent to the correct active user account for the care worker.