as always, I have tried to learn myself, I have put this code into the custom css file
.input-group-addon, .input-group-btn {
max-width: 100%;
width: auto !important;
}

#osm-singup-page input {
max-width: 100%;
width: auto !important;
display: table-cell;
}
Kindly confirm if this is correct.
Thank you so much

Hi Lee,

Would you mind create new ticket to continue this issue please? create it on here www.jomsocial.com/submit-support

Forum is bit useless since we update the site, so in the future we glad to use new support system :)

thank you