Text disappears when typing "ff" using FDOT fonts

I have encountered an odd situation using FDOT fonts in Microstation CONNECT. Our client requires this font using sentence case (upper & lower combo), but every time I type a word containing a double f in lower case letters, such as "offset", the text disappears. The problem does not occur with other fonts, nor all upper case. See screen shot for example. Has anyone else encountered this issue, and determined a cause/solution? Thanks.