Capped to 15 messages every 3 hours as a plus user?

A few days ago, I remember posing around 30 to 40 questions in three hours and doing extensive research on various topics.

However, for some reason, starting a few days ago, whenever I post few as 15 messages to ChatGPT, I see the following message:

You’ve reached the current usage cap for GPT-4, please try again after 11:02 PM. [Learn more]

When I press the “Learn more” button, I’m redirected to this page:

This appears to be a survey form, which is not what one would typically expect from a “Learn more” page. I cannot find any specific limit mentioned on this page.

Each time I post 15 messages in ChatGPT-4, I find myself blocked from using ChatGPT-4 as a plus user for several hours.

I am wondering if it’s me who’s being barred from asking questions or did they change the limit? I clearly remember the limit used to be 50, so I anticipated an increase in that limit rather than a decrease.

Only 15 messages every 3 hours for US$23.60 (Rs. 1,958.78)? Really?