The Speech to text in Co:Writer Universal is an iOS ability. The Enable Dictation setting does not get set properly when the devices iOS is updated. To correct this, Enable Dictation has to be toggled off then back on through the devices settings.
Navigate on your iOS device to: Settings>>General>>Keyboards>>Enable Dictation
Toggle the Enable Dictation Button off then back on.
Now go back into Co:Writer and check to see if speech to text is now working.
(Not all versions of iOS or iOS devices support Dictation. If you do not see a Dictation option in the devices settings, you will need to contact Apple to see if your device and/or iOS support Dictation.