Why is my email address in parentheses when I get a pop up to enter my password ! It did not do the start of initial Apple ID set up.s

My email when sent pop up from Apple are now strange my email is in parentheses “myappleid@icloud.com” and Apple is sending pop up message with my Apple ID as MYAPPLEID@ICLOUD.COM . I have been having sign in issues, registration issues ,validation my identity with both Apple but worse with Verizon and maybe due to MyVerizon app which I deleted and then added. I also am not able to get Apple update but Verizon said I could buy add another data plan use Hotspot for my Apple software updates as I can not manually download due to download now is grayed out.