Which app are you trying to assign? Is the user added to correct group? Intune doesn’t support identity for google accounts.
Problem publishing applications at device android - intune
After creating a group, there will be no purpose and associating that group with a user made a period of an internal application to a device.
The application does not appear on the company portal. The device is an Android with work profile. And the managed google account is already associated. What configuration item may be missing from the intune for the application to be applied to the device as available?