When you are not receiving emails on the gmail account. it means something is wrong with the user account or password. so you need to remove the current settings and then reactivate that account.
1. first of all, you need to delete all mail filters.
2. let's go to the forwarding settings and then deactivate it.
3. Go to the imap/ pop server settings and then make sure it is configured with the required settings.
4. some users are unable to receive the emails because of the incorrect mail settings. so you need to remove the current mail settings and then update them again.
For more details, you need to visit: how to fix gmail not receiving emails?