Lightbulb [Q] switched carrier issues/software

so I switched from Verizon to a smaller cheaper company called page plus. and the retailer for page plus flashed my phone or whatever he did to be able to make the carrier switch. im now having an issue where a Verizon app pops up asking for my login but only on Wi-Fi. its not taking me to a browser page but an app popup. I tried logging in with my creds but it does not recognize to account.. being that I have cancelled with them in all. ive also tried removing any Verizon bloatware I could see (i.e. anything that looked suspicious) but still a no go. anyone got an idea how or what I can do to fix the issue? like is there something specific you know of that I must delete? thx 4 any help provided!