For me the credit does have a pulldown. Once I pick a vendor, another appears populated with their products. So this is some Javascript programming that apparently isn't working with whatever browser you're using. I'm seeing the fields work fine in

• Google Chrome Version 40.0.2214.93 m
• IE Version 10

Just tried it and as you say it works in Google Chrome so thanks for that, stupid of me to not think of the browser.  It stopped working around the time of the changes so I put it down to that.

 

 

I use Poser 13 on Windows 11 - For Scene set up I use a Geekcom A5 -  Ryzen 9 5900HX, with 64 gig ram and 3 TB  storage, mini PC with final rendering done on normal sized desktop using an AMD Ryzen Threadipper 1950X CPU, Corsair Hydro H100i CPU cooler, 3XS EVGA GTX 1080i SC with 11g Ram, 4 X 16gig Corsair DDR4 Ram and a Corsair RM 100 PSU .   The desktop is in a remote location with rendering done via Queue Manager which gives me a clearer desktop and quieter computer room.