I've added it like you suggested and it is still happening. One of the things I also did was run it with AV off. still happens. I just find it weird its only happening on select trainers. *shrugs*
What browser are you using and what security software?
Google Chrome and AVG
Either disable safe browsing in CHROME (not easy to find anymore thanks to update) or switch to MS Edge for this site, and you should be fine after that, CHROME had an update to it's security and it is just horrible. Using my memory for this so may not be exact
Click the menu button (⠸ in Google Chrome.
Select Settings from the menu that has appeared. (may need to scroll down and click advanced)
Select Privacy and security. (you can also open chrome://settings/privacy to go straight to the Privacy and security settings.)
Now click More for the Privacy and security section.
Look for Safe Browsing toggle it's buried in there somewhere.