Have no answers, just thoughts. When you said you cleaned the nozzle....not sure what that entailed. It's happened to me several times with expensive hair spray. On another spray glue can I have it says if you get it on your skin to wash it off with soapy water so maybe you could pour soapy lukewarm water into the spray "hole" on your can and then twirl a very fine needle in the hole.
Do you have another nearly empty 505 can you may have saved that you could exchange heads with ?
Can you take it outside and try to spray it upside down? It's worked for me with spray paint.
So very frustrating I know and, with the persistent elevation of prices , doubly so! Good luck!