Offer other contact information such as a cell phone or email address if you will check it (i.e. on vacation). DON’T: Be too informal, even if you are creating a humorous message. Give a prolonged sales pitch in your voicemail greeting message. Waste a caller’s time with an excessively long greeting before they can leave their message.
Some people found success in fixing their voicemail woes when they temporarily disabled

Voicemail is a service that lets callers leave a voice message for you if you aren't available to answer your mobile phone. There are both free and paid Voicemail options to …
Android phones can access voicemail by holding down the 1 key on the dial pad until the phone dials your 10-digit phone number. You will automatically connect to your mailbox and be prompted to enter your temporary password; this password is the last 4 digits of your phone number followed by the # key. Start the Google Voice app. Tap the three horizontal lines at the top left of the screen (sometimes called a hamburger menu), and then tap “Settings.” In the Voicemail section, tap “Voicemail greeting.” Tap “Record a greeting.” How do I access my voicemail? To call your voicemail on an Android phone, simply open your phone’s dial pad and hold your finger down on the “1” key. You can also call your voicemail from a different phone by calling your own number and tapping the pound key. How do you check your voicemail?