I too am having the quickbooks "Unable to see detail screens" when the Dashlane Extension is installed.

I have this problem with both Firefox and Chrome.  If I disable the Dashlane extension, the problem in QBO goes away.

I also made sure I've installed the very latest version of the Dashlane extension (6.2247.1 as I write this).  The issue remains in this version.

So, I'm wondering what the solution is - Is there a way for Quickbooks Online and the Dashlane password manager extension to co-exist?    Please reply with what your "resolution" was to the issue (hoping that it is something other than "Uninstalling the Dashlane extension"

Thanks!