Also, for what it’s worth, on Safari, it starts out as using the https prefix, but if I look at other tabs on the banner, up to Contact, then go back to Home - it goes back to http.
So you have confused links. Somewhere you are sending it back to http, instead of https. Which will confuse it no end.
Also worth checking this link. https://securityheaders.com to do a check of your website security. It’s not good at the moment
cheers
Robert