make sure APN is correct for PM. Should be sp.mb.comGo to Settings, click on Mobile Networks, Toggle "Allow device to use mobile data", click on Public Mobile SIM (Sim 1 or Sim 2), go to Access Point Names and add the PM APN if not there
There may be a conflict if you are trying to activate it on top of your current service provider. I suggest you remove the old SIM, open the PM app on WIFI and activate the PM eSIM. Also ensure the APN is correct for PM which should be sp.mb.com