First, I selected the folders, right click, PUT (pop-up with options), created some masks to not to upload files like *.mp? , generate script, copy to clipboard and finally OK to upload everything the first time (around 200MB, 3300 files). It took a few minutes.
Then I created a basic task scheduler following your web page steps.
I edited some schedule and other properties after finished the task to execute it each 10 minutes after login, execute even if no AC connected...
At the end, from the Task Scheduler panel I clicked on "Execute" and the task turned from Idle to In Action (My system is in another language so maybe English translations are not accurate).
As said, first time transfer was 3300 files, 200MB but next transfers are no more than 3 files (less than 1MB total) each 10 minutes.
My question is why each backup takes so long. Task Scheduler displays my task In Action (Executing, whatever) for more than 7 minutes (I didn't keep seeing it until it finished)
Does it take a long time to compare dates/sizes of the rest of the files?