Initially, could you please send me a screenshot(omitting personal info) of what you’re seeing so as to have a better understanding of what your concern? Any additional info on this would also be very helpful.
Initially, could you ensure if there are any third-party apps that could be blocking/hindering the app from running, like an antivirus? You could try temporarily disabling your antivirus or security program or configure your firewall to work with Dropbox.
Also, could you by any chance be connected through a work network? If you are, check with your company’s IT department, since there could be a potential update on your firewall settings which could be affecting your connection.
I’d also recommend having a look through this Help Center article for more suggestions in case you come across something that might help resolve your concern.
If this doesn’t resolve the issue either, I’d recommend moving this discussion to email due to account-specific info that may be required to further investigate. In this case, I can contact you directly via email to your email address that’s associated with your Forum profile.
Let me know how it goes and I’ll make sure to get back to you as soon as possible. Cheers!