Last night I was working on my husbands pc and decided to enable the passwords feature on his Avast so that I could have access to my passwords. I went through all the steps turning on sync and authorizing from my pc etc. Now all the newer passwords that I have created in the last month or so are gone - from both computers. Is there any way to get them back? 
Hello, I have checked audit trail of your synchronization group operations and I can’t see any deletes to be done in the chain of operations, so most likely the data are there but are just not visible for some reason.
Could you please start both computers make them running and keep them connected to the internet at the same time
add new record manually (e.g. secure note) on each device and check they are synchronized?
means note on PC 1 appears in notes on PC 2 and vice versa
I forgot to mention that you can manually invoke synchonization operation on each device.
On windows open Avast application
Go to Settings
Pick tab Passwords
On that tab find button Sync now
That will trigger synchronization process
Once you hit this button on each device then once this invoke finishes you should have all actual data
You should also make sure that streaming updates enabled. You can find this information in settings on tab Update in section virus definition by expanding settings section