The Provider configured custom ASCII attributes for the Online Store in the PBA Provider Control Panel at System > Settings > Attributes.
After upgrade to PBA 5.5 custom ASCII fields in the 'Additional Information' section in the Online Store checkout screen do not allow dash character ('-'). On attempt to place an order the following error message appears:
<ATTRIBUTE_NAME> must contain latin characters only. Please correct.
The same error message is displayed when trying to enter value with the dash character in the ASCII attribute on the 'Additional Information' tab in a customer account properties in the PBA Provider CP:
Issue has been confirmed as the defect PBA-52744.
The problem is resolved in the PBA 5.5.3, update PBA to this or later version.
In the meantine, as the workaround, change the type of attributes from "String (ASCII)" to "String". This way there will be no attribute validation in Online Store during order placement, everything else will work.