It seems hit or miss when posting images will work for me. Is there another way besides attaching through the Nexus?

I use imgur with anonymous e-mail account (Protonmail). Then you can simply add images with the img tag.

When attaching images via Nexus, try to resize them to smaller size (e.g. 1920 by 1080 pixels). Images that come from a camera are often much larger and that may cause hiccups to the server (maybe).