Why won't JBL Party App connect to my iPhone?

Can someone please advise.i just bought the JBL PartyBox 120 I have tried so many way to connect the JBL party app to the speaker with no joy on my iPhone 14 Pro Max so I decided to try an my iPad Air and it’s work right away please can someone tell me what I am doing wrong on my iPhone 14 Pro Max I was thinking it could be that the app doesn’t support the latest apple software.

[Re-Titled by Moderator]