Please help with login issue

[Scream And Fly]

Hi all,

My site is at www.screamandfly.com. It's a VBulletin 4-based site.

Beginning this week, many users are reporting that they are needing to log in to the site every time they visit it, even with the "remember me" box checked. I had this issue myself when I left my computer idle for an hour and came back to my site, and I had to log back in again.

I'm stumped because nothing at all has changed on my site in a very long time - over a year. I've never had this issue and I'm not sure how this could begin happening with no changes made to the site.

Users are reporting this with Firefox and Chrome on desktops so far, and I've been able to reproduce it on iOS with Safari and Chrome.

I'd be extremely grateful for any insight into this. More and more site members are messaging me about the issue.

Thank you, everyone,
Greg