Thank you for reaching out to the Community. Let's figure out if this is a browser issue. We can try logging in using an incognito window. This way, we'll know if it's your regular browser, which causes this unexpected behavior.
Follow the shortcut keys, depending on what browser you're using.
Google Chrome: Ctrl + Shift + N
Mozilla Firefox: Ctrl + Shift + P
Safari: Command + Shift + N
Microsoft Edge: Ctrl + Shift + P
If it works fine, go back to your main browser and clear the cache. It helps to troubleshoot and increases the performance of your browser. Also, they can use other supported browsers to better isolate the possibility of a browser-related issue.
Feel free to drop a comment below if you have other concerns about tagging transactions in QBSE or other inquiries. I'm just around to help. Take care always.