When I was applying for my covid Sandcastle visa on line i had a similar issue it turned out I was getting a space after I input passport no. Eventually all it took was a back space to clear the problem.
Last Friday I applied for a 60 day visa , it also showed pending, a couple of hours later it showed complete , then this Wednesday I got my visa. This was in uk
I also have never ever been asked in Thailand for either money or return ticket, only time I have ever been asked was is in Cambodia when I was flying back to Thailand from Pnom Penn and they wanted to see ticket to leave Thailand