Solar edge 3g the Ethernet ? And frequency of cell card renewal

So I got an email last week about our 2g cell card for solar panels ending service April 2… I called the local installer first ( use to be blue sky but went out of business? So we transferred to new company) they are telling me I don’t have to worry about it because I don’t have 2g because it would have been disconnected and I don’t have 3g…. How do I know if I have 4g because I then called solar edge monitoring and they’re saying I have 3g dispite what the installers are telling me … Either way I’m going to install Ethernet because i don’t want to pay to renew a card ….. Also I wonder why we’ve had monitoring service for 6 years and haven’t had to renew a cellular card , is this normal ? And yes it currently works fine .