Issue with Captive Portal

Currently, we are facing this issue with Captive Portal.

The captive portal is not showing up as the certifcate is not secure:
image

The certificate is showing :
captive-portal.peplink.com

The login captive Portal is

Equipment - B One 5G
The current firmware is
8.5.3 build 6030

Please advise.

I had simmilar issue what i did was remove captive portal, reset balance and creat new one.