Yeah this has been happening to me for at least a month.

All versions of chrome, on two different PC's and also on mobile.

I actually found a fix, you need to go to Chromes site settings for OTCA (chrome://settings/content/siteDetails?site=https%3A%2F%2Fwww.otca.com.au), scroll down to "Insecure content" and choose allow.

But... that doesn't sit super right with me.