I experienced exactly the same issue month ago, actually Public mobile updated months ago, please update to the following APN parameters, pay attention to the APN type part.Hope this can help you out of thereAPN: sp.mb.comProxy:Port:Username: <blank>...
ok, actually PM provides an official guide here, hope it can provide some more accurate informationhttps://www.publicmobile.ca/en/on/get-help/articles/set-up-data-on-an-iphone
update according to the following information, then it should workAPN settings Name: Public MobileAPN: sp.mb.comMMSC proxy: mmscproxy.mobility.caMMSC: http://aliasredirect.net/proxy/mb/mmscMMS port: 8799MCC: 302MNC: 220