Unable to login from anywhere on this site unless it's on the home page only.

I noticed when I get a notification email about someone replying to one of my posts, which gives the board's URL, which I click on and it takes me directly to the forum post, then from there I try to login and all I get is:-

Warning
The security token did not match. The request was aborted to prevent any security breach. Please try again.

So to log in, I have to click the 'home' button, login, then go around searching for the post that was replied to.

Sorry to hear you are having problems. I tend to log in then I check the status notification on the right-hand side. I realise that isn't immediately obvious if you are viewing the site on a mobile device so I have tweaked the layout to hopefully make it easier to see. For the login, not sure why you get that error as I tried and it was okay for me. What web browser are you using?  I will do some more investigations to see if I can uncover anything that might cause this.

I'm using the latest Chrome browser (Version 98.0.4758.81 (Official Build) (64-bit)) on Win10 (updated 2 hours a go), with some security plugins that stop a lot of 'on-site' advertisements, and I checked them by disabling them completely, and I even tried it in incognito mode with no plugins, and both did the same.