Since maybe a week ago I can no longer see any downloads in queue...?
I tested by creating a random course and sent to the units, but nothing...

I confirmed this as well. The changes do appear in Garmin Express as updates to sync, but not on Garmin Connect Web. I would suggest submitting a case to Garmin Product Support.
It seems like Garmin has intentionally removed it so your best way is to contact Garmin about it.
Support: https://support.garmin.com/
Submit idea: https://garmin.com/ideas