Currency fields are not AJAX editable in version 7.5.0
Issue introduced in version 7.5.0, currency field are not editable in detail view using ajax.
The problem is in file /modules/Vtiger/models/Field.php
in line 523 to fix it
Replace
self::UITYPE_CURRENCY_AMOUNT,
with
self::UITYPE_LINEITEMS_CURRENCY_AMOUNT,