Loss of mobile data connection

[jenski2]

Since I've changed my plan and increased my data ,I have had problems with having no data to off and on  when it's on there is no 4g showing by the signal which is weird. I do have a old sim card but is still 4g I'm on a 5g plan. Could this be the problem. 

[bristolian]

Your plan changing will be immaterial here.

If 4G/VoLTE isn't showing next to your coverage indicators, you could be using 2G or 3G - this would cause a significant degradation. Presumably you have restarted your phone as the first step?

Do you have this same issue in multiple locations, or just specific ones?