I recently changed to Virgin on a sim only deal from Plusnet. Since the change over I have found that when displaying the "H" by the signal indicator I struggle to make calls and receive them. I have also found that if driving through an area with 4G and entering an area where it changes to "H" I often lose signal and this takes some time to come back.
The problem is getting to the point when I am considering changing networks. Is there anything I can do to change things or improve this?