pd dashboard can not find prometheus

[wfxxh]

Bug Report

Please answer these questions before submitting your issue. Thanks!

What did you do?

I do nothing

What did you expect to see?

The reasion why can not find prometheus

What did you see instead?

Can not find prometheus

What version of TiDB Dashboard are you using (./tidb-dashboard --version)? v5.4.2

The pd dashboard status is ok at first. But after some time,it show can not find prometheus. The status of prometheus is ok.And when i specify the prometheus address,the pd dashboard worked.

This is my cluster status

This is prometheus log

This is pd log