DKIM test failure

[R.B]

I created a new domain name and generated the DKIM key. Because the domain name was deleted due to an error, I can only try to re-create the domain name, and the DKIM key. In the management background DNS test DKIM is passed, but I send the test email to gmail, showing DKIM is FAIL, I checked that the DKIM key (Selector s2019100xxxx) that sent the email is not the last generated KEY displayed in the background, but the key generated when the domain name was deleted by mistake for the first time. I tried to delete the key and regenerate it, but Can not solve this problem.
Hope to get your help! thank

[R.B]

The problem of restarting the host is solved!