Problem occurs after setting border-radius and border together_html/css_WEB-ITnose

I wrote a mobile page and wrote border: 1px dashed #e2e2e2;border-radius:20px; I found that on some mobile phones, the rounded corners were applied to the border and not to the entire area. After removing border:1px dashed #e2e2e2, the rounded corners function normally. How to solve this?

Reply to the discussion (solution)

Please give me some advice. . .

Does anyone know the reason?

Maybe the background color and border are not on the same div. If the background is on that div, you need to add border-radius on that div
Watch the online demo.

It may be that the background color and border are not on the same div. If the background is on that div, you need to add border-radius to that div.
See the online demo.

My background is on the same div. In fact, it is normal in many browsers, but there is a problem on some mobile phones. . . Thanks for your answer.