That usually indicates HDCalling (aka Advanced Voice, VoLTE, LTE calling) was turned off. What phone do you have? The setting depends on the phone.
We certainly want you to be able to use your phone as intended, JANJON4. The issue outlined in your post makes sense, using data while making a call requires a solid 4G connection. If your signal changes from 4G to 1X when you are on a call, the connection is not strong enough to handle calls and data at the same time. What is your ZIP code? We can check the area and see if any service/signal issues are noted for that area.
Also, you can call and browse if you connect to WiFi when cellular signal is not strong enough.
Follow us on Twitter @VZWSupport
If my response answered your question please click the �Correct Answer� button under my response. This ensures others can benefit from our conversation. Thanks in advance for your help with this!!