PaintBBS

I have implemented several possible fixes on my side.

It seems that the issue may have been caused by Web Workers not functioning correctly in certain environments or browser settings.

I have now disabled the use of Web Workers and applied additional measures that may improve compatibility.

To confirm that the problem has been resolved, could you please try publishing again using a very simple test sketch — something small that you wouldn’t mind losing, rather than a full illustration?

Thank you very much for your time and cooperation.

It's possible that your network provider's security settings were rejecting the posts, likely triggered by the Web Worker. While I can't be certain, I have stopped using Web Workers to avoid this conflict. I hope this resolves the issue.