Dashboard not updating

I have exactly the same problem since the last release. However, I'm running it on a raspberry pi 3.
No statistics are shown on the dashboard and no long-term logs are available - "Query log" throws a popup message indicating "An unknown error ocurred while loading the data". Everything was working before the update.

"pihole -d" shows nothing special.
Interesting is that I'm somehow running pihole core 3.2.1 and I cannot update to 3.3 ("pihole -up" shows everything up to date) while FTL & Adminpage have updated themself to v3.3 and v3.0.
Edit: "cd /etc/.pihole && git fetch --tags" fixed the version mismatch like described here.

I'm running dnsmasq v2.76 so that should not be the problem why it does not update the core to v3.3.

I've read it a couple of times here in the last hours that more people have the same problem like I have.
Do you want me to send a debug log aswell?