That shouldn't matter. All posts are technically link posts with a url. When you upload an image "directly" that just means the images gets hosted by the image-rs server running on your home instance, but the post works exactly the same way. (You can see this by how the image upload changes into a url once done. You can still edit it and use a different one, or copy it, and use it somewhere else.)
You probably just got lucky, worlds current federation issues seem randomly intermittent.
PS: Glad I found something nice. You are such a big part of these communities and I want to give at least a bit back :)
That's exactly what I'm trying to inspire. My entire reason behind the effort is that I want MORE, preferably stuff I haven't seen :D