Any change i try to do in pihole web interface are not saved and gone after reload.
Also Networking tab under web setting is showing "unknown" addesses.
Chrome v 55 stable
Cleared cache, tried FF and IE and Edge, still the same.
Also it's verry laggy 
Which OS are you using on your Pi-hole?
Official Raspberrian on raspberry pi3.
Please run
sudo pihole -r
to see if this fixes the issue for you. Chose "Repair".
Oooh, how i love this comunity !!!
It helped, i think i haven't the webGUI password at all
I have to donate again 
Also saved the command for future fixes 
Thank you very much !
My pleasure. I am happy to be able to help
I'm noticing something similar, I added 2 domains to my blacklist after a while they disappeared. Oddly the list I had prior to the upgrade stays intact. Used nano to to view the list from cli and it the entries have been updated.