Same issue here. for the love of God, I pay for family and would love to have this fixed. Opening Lastpass the app to copy and paste passwords is just not a great solution when there should be better integration with Safari, etc.
This issue is going on for weeks. Looks like LastPass doesn't care about Mac/Safari users. Another indication that they don't care is, until today no announcement if or when a native Mac Apple Silicon LastPass will come.
It's time to move to 1Password.
4.95 does not correct the errors for me. I did a complete uninstall and reinstall of the Lastpass app. It seemed to work as expected again until I closed the app. Once re-opening it, the dreaded blank window reappeared. The Safari extension does seem to "work" but you have to login each time you open/close Safari (and the blank window still appears too). Safari logs you out every time you close it. Looks like you all need a little more testing...
It works now. Then if I close the app I get the blank page again but if I use the Log In from the last pass menu it works again.
I can use it now, but it's still far from being ideal.