I remember, I had similar issues in the past. I think it depends mostly of which client you're using, relay connections, etc.
I think connections is the main problem. The second problem is clients never notice when you have poor connection, and event will just fking disappear after you push send button. Because clients can't predict what relays will do and if connection will be still bad or good enough to push event to relay at the exact moment when you try to publish something.