Sentinel-2 L1C bucket not updating?

It’s rather that ESA ground processing/distribution has issues more common than usual.
The thing you noticed is related to “delayed production” (see news). For the last couple of days S2 L1C were distributed at half the usual volume, e.g. 5000 products per day. There were missing S2 L2A as well, but not that much. We have notified ESA about it on Thursday and they’ve put this notice on Friday.
This morning (CEST) about 22.000 products were dumped to the Hubs (update, then in the evening another 10.000), probably the missing ones from the past days. This caused backlog, which is difficult to clean at once. I am guessing it will be cleaned in a day, unless there are some further issues.

In general, though, there are quite some issues with production/distribution in the last few weeks, starting with the fire in OVH data center, which also hosts the Hubs. If you check the news for the last couple of weeks, you will get the feeling.
https://scihub.copernicus.eu/twiki/do/view/SciHubNews/WebHome

I suggest you check the Copernicus SciHub news whenever you notice missing tiles here…

Thank you very much for the helpful reply.