Okay I'm working on my schematic and making my own blocks, put my connections in but when I try (sometimes) to place a wire it won't stay connected. It just disappears but will wire to other connection.

The missing connection is at B1 it won't stay connected and I don't know why. I've gone in removed all connection points and inserted them again to have it continue doing this. I'm not sure if I have a possible graphics issue or I'm not doing something right. 99% of the times I don't have this problem but this is driving me crazy and I don't know how to fix the issue.

Thanks for any and all help.