This is a very weird situation as I have never seen such anomaly. I created three Decimal fields on an Object and the data in these fields are populated by a trigger. Everything is fine when I see these fields. However, the same fields display incorrect format when viewed using a different user. The Commas get replaced by a Dot and vice versa. Screenshot below:
When I (Admin) see the record, the field behaves properly.
When Viewed through other user - commas get replaced by dot and vice versa.