when your bridges go down, you don't optimistically retry
When you're using bridges, and your network goes down or your bridges go offline briefly, we should see this log line:
Sep 28 15:36:02.507 [notice] Application request when we haven't used client functionality lately. Optimistically trying known bridges again.
but it isn't happening.
To upload designs, you'll need to enable LFS and have an admin enable hashed storage. More information