There are two ways that text can be formatted. You can select a field while in layout mode and specify a format--whether conditional or just in the inspector.
Or you can format specific text in the field--either by selecting the text and applying a format from the formatting tool bar or by pasting formatted text from another source.
The format applied directly to the text supersedes the format specified for the field while in layout mode.
To remove the format from existing data, use TextFormatRemove ( fieldNameHere ) with the replace field contents tool (show all records first). To keep out such formatting in the future, set up TextFormatRemove (Self) as an auto-enter calculation with the "do not replace existing value..." check box cleared.
Thank you for your reply, it was very helpful. Another way I resolved the issue was by deleting the text and then re-typing it. For some reason this triggered the font I had selected in layout so I can only imagine it was some form of refresh issue. But once again thank you for your reply which will be useful in future
Retyping can definitely remove a text format applied to the data being retyped. It will just take a while as your are fixing the problem one character at a time while my suggested methods do it all in a "Batch" operation.