bug: warning text disappears

the problem is that the warning message
“Your booking and personal information exactly matches another booking. If this was not caused by refreshing the page, please call us to make a booking.”
disappears after less than a second.

it worked with 2.5.1 and does not work anymore since 2.5.3 (or 2.5.2)

introduced with change in booking-form.js

else {
 clearPrevFieldError( 'date' );
}