After maintenance on my computer I find that a sigma will only diplay as σ at the start of a word. In all other positions it comes out as ς, which, of course, should only occur in final position.
Now find that the problem seems to be only in Word, not in PowerPoint and that you can correct to the medial form of sigma by highlighting the offending chracter and typing over it. Still a nuisance not to have this done right automatically.
What version of Word are you using?
Just out of curiosity, if you type a text that has bad sigma rendering, does doing a global replace of sigma by sigma correct them? If so, this might be an easier way to work around the problem.
This is a known issue in Word and can be corrected following the instructions here: https://help.keyman.com/knowledge-base/43
Many thanks to both of you. I’m using Word 2007 and unchecking the ordinals autocorrect does solve the problem, which had previously occurred even without an accent or breathing on the following vowel, If you have a number of sigmas to correct then find and replace does work, though, of course, you need to vet each instance individually or the final sigmas will be changed as well,