Error pasting the same set of data in the purchase insurance page

When I continuously copied and pasted the same set of numbers on the insurance purchase page, the webpage recognized the error, and the situation appeared multiple times. The number I tried for the first time was 40, and the number 40 was still wrong for the second time. The last time I tried was the number. 80 also has a problem, the following is my screenshot evidence, I hope the project party can verify this error