Hi Gina, thanks for getting in touch.
Rafael here from Trello Support, I hope you're doing okay!
In this case, seems like something on your browser is causing the issue. Please take a look at this guide - https://support.atlassian.com/trello/docs/troubleshooting-browser-issues-with-trello/
If the issue still happens after you tried the steps indicated in the troubleshooting, let me know or feel free to raise a ticket with us here - https://trello.com/contact
All the best,
Atlassian Support - Trello