Why do cards disappear?

[Sue Mitchell]

I work on both a Mac and a Windows 10 PC. Trello works fine on my Mac, but on the PC, cards won't stay where I put them. I'll move them onto another board or column, and when I come back later, they're back where they were before. Sometimes it takes me quite a while to find them, and it basically makes Trello unusable on the PC because I transfer cards between boards and columns often. 

Any ideas on why this may be happening?

[Michael Pryor]

Are you using a web browser when doing this? Or the desktop application?

[Sue Mitchell]

Oops, sorry, should have mentioned I was using Chrome.