My phone won't send icmp/ping unless WiiFi connected. Can this be fixed? I have local terminal access and ping command works when WiFi connected, but not when connected via cellular service. I get same results using ping within other apps.

Can this be "fixed?"

Phone is Verizon, brand Samsng J7 V, software build M1AJQ.J727VVRU2BSA1
Mobile network operaters block outbound ICMP echo sometimes, and inbound ICMP echo most of the times. You can use nping to use TCP or UDP for pinging if you know some open port on destination. Or you can use a third party service like https://ping.eu/ping. But be sure your endpoint is responsive to echo requests, some routers and PCs are also configured not to respond. E.g. on Linux or Android to block echo requests:

echo 1 &gt;/proc/sys/net/ipv4/icmp_echo_ignore_all