ChatGPT+ on Firefox. Model Drop Down Missing or NOT Working

I just bought ChatGPT Plus. I am using the latest release of Firefox (114).

(1) I don’t get the Model drop down box. Just a choice of GPT-3.5 and GPT-4.

(2) Even though I always click the GPT-4 option, it behaves like I am using the GPT-3.5 model. I can NOT get it to actually use GPT-4.

Before I start using the API: How do I get the Model drop down box and use GPT-4 model. My screen shows that I am in the ChatGPT Plus that I paid for.