Issues pairing the Mantis Braille Display to an iPhone 17E

Hi i wonder if someone might be able to offer me some advice please - i'm at a dead end re trying to get my mantis braille display and phone to work normally. Basically the phone tells me both are connected, but all it reads on the mantis is "braille display" and pressing the thumb keys or swiping the phone screen doesn't change anything. I have tried multiple times deleting (forgetting) on both devices, turning bluetooth off on both devices and leaving them like that overnight in the hope they would right themselves, but they are still behaving in the same way this morning when i attempted to pair them again. Strangely mantis will pair to my other phone (an SE third gen), running the same latest version of IOS, but this is of no help while i'm out doing courses and so on and need my 17E (the one with the active Sim). It really isn't practical to have to take two phones out with me just because my braille display will only pair with one. Is there anything else i could try in order to fix this? Thanks in advance for any advice.