MQTT Engine not connecting to MQTT Distributor after Ignition gateway restart

Hi,

I am using the latest version of ignition and MQTT modules.

When I restart my ignition gateway, the MQTT Engine status stays not connected, until I edit the MQTT server settings and click save WITHOUT making any changes.

I am using self-signed SSL certificate.

While it is not connecting, the logs show: Error while accepting secure connection from /{URL}: Received fatal alert: certificate_unknown

Again, If I just click save without changing anything in the MQTT server setting in the MQTT module, the connection is established.

I would like to know why this happens, and what is a possible solution?
Thanks