If you remove the iron stuck in the corner (default 'F' key), does it flow correctly afterwards, or does it get stuck again ?
Btw, there is a major change on the way items are conveyed on belts coming within weeks with 0.12. I bet this won't be an issue anymore then.
I was a little unclear in my ...

Again in 0.11.22. First time for after several hours of play. First tried to rotate/re-place the belts in the bend, but it didn't change anything. Just picking a few up will release them and I had no problems for the rest of that session. First time I've seen this, but I have only been playing it ...