This always worked seamlessly - until the latest Firefox update - 89.0
Now, no logins/passwords are transferred to the appropriate login/password window, and the LastPass three-dot logo doesn't appear either.
I've "down-graded" back to the reliable 88.0.1 Firefox until it's sorted.
It'll be Mozilla's fault - not that of Firefox, I'll bet.

This morning I cannot log in to LastPass, why ???

For some reason this addon refuses to download and indicates a problem with the network connection, which there is not.

Firefox updated and removed my automatic log in. I don't know my master password and the one time pass recovery option fails. Their alternative? Start a new account. Great! All my saved passwords are lost. Time to try an alternative product.

The free manager is useless now and the premium is way overpriced. I recommend Bitwarden instead.