Turn by Turn Indication

You can try my datafield app which improve ability of turn by turn navigation for Fenix 5 a little.
https://apps.garmin.com/en-US/apps/529c0c1c-5f80-4f66-bb19-fca6bec0e5c0

Each time I want to follow a course I have only the flag showing total distance before arrival...

Post a link to one of the courses you have created that has the problem.

Yesterday I ran this course as a trail run and had TBT directions, though I would prefer to not have had them as it was a marshalled race anyhow.

You can try my datafield app which improve ability of turn by turn navigation for Fenix 5 a little.
https://apps.garmin.com/en-US/apps/529c0c1c-5f80-4f66-bb19-fca6bec0e5c0

it shows the text label for the turns? Nice. I will definitely be trying that, I'm disappointed Garmin stopped showing that.

Yep, it can show up to 15 characters for any coursepoint.

Is there a possibility to use this datafield also on Fenix 3?

I sent your course to my Fenix 5 and the opened the FIT from the Course folder in the watch using fitFileExplorer. The course points were in the file as they should be. Sorry, I don't know why you are not being alerted to turns.

I use my F5 for running, and only as a backup device for cycling. However, in the summer, I did a two week Skandi tour on the bike with my Edge doing tbt. I think that the F5 was also doing tbt but I am not sure as it was not my primary device.

Hi TrippyZ,
I did the same operation as you: export via Garmin connect to my 5S and open with fitFileExplorer and no TBT indications are present in my file.
It seems to confirm that Garmin blocks the TBT instructions when exporting to 5S models but not to 5 models... It's a very silly limitation. I'll try to email support to have confirmation (since I don't believe they'll change this behavior).

Seems highly unlikely it would be selective like that. Is there anything else odd about your watch in Connect - for instance, do all your activities have elevation correction turned on? Wondering if there's an issue with the database not identifying your watch model properly so not sending the right file to it.

Guys, in plotaroute, is there a way to manage the number of "Course points"

My Fenix 5S only allows 50 per route.

In plotaroute, I have 38 turns (a trail run). But when I download my course as a FIT file, I seem to have 75 course points.

I don't seem to be able to list all 75 course points in plotaroute to manage these. I really just want the 38 turns that are listed in Directions.

Any tips?

I think you've left Turn Warnings enabled in the plotaroute download. That creates an extra coursepoint just before each turn, to warn you that you are approaching a turn, so every turn uses two coursepoints instead of one. You do not need these for a Fenix 5 series watch, as they automatically generate warnings ahead of the turn anyway. Try setting Turn Warnings to no and see how that works. (Not sure why you are seeing 75 rather than 76, though).
Other than that, how is the site working for you? (It's not mine, but I wrote the library that creates the FIT file).