Thanks you that's good information but unless Network-Manager is conflicting with something I'm happy to leave it just as I have a bluetooth manager for my keyboard.
My Android phone has network settings and my cellular provider seems to need at least one of them to be happy. I know some providers "just work" with Leste. It's curious that Leste uses a PMOS routine during boot and I'm coming from PMOS which uses modem-manager but of course I did have to give it this command to start talking "mmcli -m 0 --3gpp-set-initial-eps-bearer-settings="apn=RESELLER,ip-type=ipv4".