Is there any impact on existing sessions when updating the server certificate of Managed WAF?

In the process of updating the server certificate in Managed WAF, it is not necessary to stop and restart Managed WAF, but the existing communication is disconnected at the time of updating.
A new certificate will be used from the new session after the update.
Therefore, we recommend that updating work be carried out during a period of low traffic.

Specifically, the existing communication is disconnected and the certificate is renewed at the timing of clicking [Save Changes] after editing the server policy. Settings will not be reflected in Managed WAF until you click [Save Changes].

Please refer also to Tutorial - Setting up Server Policy.