I have seen that you can edit categories to show the same in both email and calendar events, but it does not always work. I have found the first one I do from the email will appear correctly in the calendar, thereafter it refuses to show in the calendar.
Is this a bug or am I going wrong somewhere?
Can you make screenshot of your settings and post it here? I need to see it to imagine what exactly do you mean.
Go to Tools/Categories and select item to edit. You will have the windows as in the attachment. If you select a category when reading an email that contains and ics, it usually does not transfer to the calendar.
so If I have understood it well - you open some .ics or calendar item and then u want to edit some category but it does not change in that calendar item?
If so I have tested this and it works - eM Client shows message that item has changed and it needs to be closed to apply changes.
if this your case too?