Have you exported your sign from one account to another? If you've uploaded a non-standard font to account 1, used this in a sign and then imported the sign to account 2, the
font will look different on the sign if you have not also uploaded the non-standard font to account 2.
To solve the problem, make sure that the font of interest is uploaded in the account. Open the sign in Creator, modify your text layer to adjust the font and publish and deploy content as normal.
If you haven't exported a sign and you're having trouble with fonts then please contact the support team.