Why would you uninstall BP and reinstall it, you even don’t know where the issue came from ?
Take a breath and stay calm. 😉
Activate Twenty Fifteen theme.
Deactivate all plugins except BP.
check for anything is correct. If it is, you can reactivate your plugins one by one, checking after each for an issue, untill you find eventually a culprit.
If all is correct, the only thing who may bring an issue at this stage is your theme.
Activate it and see the result. If you get the same issue, you should contact the theme support.
We cannot help you for this, as it is a premium theme and we have no free access to it’s code.
Please read also here, where some basics are explained.
https://codex.wordpress.org/Debugging_in_WordPress
