Seems like it is the same courses for strengthen skills.
To me it seems like it is the always the same 5 or 6 courses for strengthen skills. Not sure if other people are seeing this but it seems like it's always the same courses and some of the other courses never come up for strengthening. Some feel like it's the same one every other day. Anyone else notice this?
I think that unless all your skills are kept on a full, golden bar status, when you hit "Strengthen" only the first weak ones are selected for practice. So basically, the strengthening option does not work for the whole tree unless it is golden, but it can be used to take a single skill to full strength easily, instead of repeating its individual lessons.
Usually I click on the skill level and then strengthen each additional level as needed. I take it the "Strengthen Skills" blue bar on the far right is something different. How does this work? I did it once yesterday and it started me from the top skill. I did it again today and it started me from the top skill again.
The strengthening option from the skill level is supposed to strengthen that skill only but the one on the right is supposed to strengthen the whole tree (up to where lessons have been completed, of course). Unfortunately, it only starts with the highest non golden skill, testing only that, so basically works for the whole tree only when everything is golden. That's what I understand is happening at least.