A backslash is seen whenever there is an apostrophe in the text of a hint message on a read only price field
This seems to occur on price field or a field that has a special character like $ and this is not properly escaping hence causing the backslash to follow an apostrophe.
Steps to reproduce:
I did test this in London, Madrid and New York, and I was unable to reproduce the problem in those versions
This issue is fixed in London and forward so using those versions would be the first recommendation. If you require a workaround, you can create a UI policy that makes the field read only which will prevent the issue from happening. The issue is only triggered if the dictionary record is set to read only.