Pre 1.2.6 the "Edit in external editor" button had two functions; One click started external editing, one more click stopped external editing.
In 1.2.6 it seems that the only way to stop external editing is to right click the note in the notes list and select Stop external editing from the context menu?
It will be fixed in the next release, but in the meantime it's ok to leave external editing on. If you don't change the file, it just won't do anything. Otherwise you can also turn it off from the Note menu I think.
I have tried using Softmaker Textmaker as my external and even if I make a change in the external and save on exit nothing happens in the Joplin copy.
Just tried this out with Joplin 1.2.6 on Win 10 with Softmaker Office 2021. When I edited a note any changes appeared in Joplin as long as when closing Textmaker both the "Save As.. " and " Save as a text file?" prompts are answered as "yes".
Thanks. I, too, am using 1.2.6, Win 10 and SO 2021. I shall have to play with this further because, whatever I do, there is no change after exiting Textmaker. I went into Textmaker Options and checked 'Display warning when saving in text format' to ensure I was saving it as such but still no change to the Joplin editor window. The only difference in textmaker is I just get the box warning me that I am saving to a text file and formatting may be lost.
I don't actually use Softmaker Office I just downloaded the trial and installed it on a virtual machine to see if I could reproduce your problem. After setting Textmaker as the external editor in Joplin it opened a note as edit-<noteid>.md and just worked. However I cannot see what benefits there are using a full word-processor as an external editor over Joplin's own Markdown editor or a code editor?
It's just what I use. I'm not into markdown and such. In SO I understand editing tables etc which is what I was trying to do in this exercise.