The most common reason hits do not appear in reporting when you indeed see hits being sent is due to a mismatch of Timestamp Configuration.
A reportsuite can be 1 of 3 options
Timestamps not allowed
If you have the mobile property OfflineEnabled:true in your ADBMobileConfig.json or you have the checkbox OfflineEnabled in Launch then your reportsuite needs to be either Timestamps Required or Timestamps Optional (this allows both timestamped and non timestamped hits to be reported)
In order to determine what your reportsuite has been configuration with navigate to Analytics->Admin->Select your Report Suite and Edit Settings and go to Timestamp Configuration.
Ensure that if you have OfflineEnabled that your report suite is Timestamp Required or Timestamp Optional, if you do not have OfflineEnabled then ensure that your report suite is Timestamp not allowed or Timestamp Optional.
Another reason for missing data is reporting is that App Management and its dedicated mobile solution variables are not enabled.
You can confirm in Analytics in the Admin as above. If it states Already Enabled (as above) solution variables and reporting are configured, otherwise you may need to Click Button "Enable Latest App Reports" to generate these dedicated variables.